EXHIBIT (a) (1) 
                          OFFER TO PURCHASE FOR CASH
                    ALL OUTSTANDING SHARES OF COMMON STOCK
 
                                      AND
    ALL OUTSTANDING SHARES OF $1.85 CUMULATIVE CONVERTIBLE PREFERENCE STOCK
                                      OF
                               BIRD CORPORATION
                                      AT
                      $5.50 NET PER SHARE OF COMMON STOCK
                                      AND
                $20 (WHICH AMOUNT SHALL NOT BE ADJUSTED FOR ANY
                   DIVIDENDS ACCRUED AND UNPAID THROUGH THE
                    EXPIRATION DATE) NET PER SHARE OF $1.85
                    CUMULATIVE CONVERTIBLE PREFERENCE STOCK
                                      BY
                             BI EXPANSION II CORP.
                         A Wholly Owned Subsidiary of
 
                            CERTAINTEED CORPORATION
                    An Indirect Wholly Owned Subsidiary of
 
                           COMPAGNIE DE SAINT-GOBAIN
 
 THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
       TIME, ON FRIDAY, FEBRUARY 13, 1998, UNLESS THE OFFER IS EXTENDED.
  THE BOARD OF DIRECTORS OF BIRD CORPORATION (THE "COMPANY") HAS UNANIMOUSLY
      APPROVED THE OFFER AND THE MERGER REFERRED TO HEREIN AND DETERMINED
        THAT THE TERMS OF THE OFFER AND THE MERGER ARE FAIR TO, AND IN
          THE BEST INTERESTS OF, THE STOCKHOLDERS OF THE COMPANY AND
             RECOMMENDS THAT THE STOCKHOLDERS ACCEPT THE OFFER AND
                   TENDER THEIR SHARES (AS DEFINED HEREIN).
  THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, (i) THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE OFFER SUCH NUMBER OF
COMMON SHARES (AS DEFINED HEREIN) THAT WOULD CONSTITUTE AT LEAST 66 2/3% OF
ALL OUTSTANDING COMMON SHARES DETERMINED ON A FULLY DILUTED BASIS, (ii) THERE
BEING VALIDLY TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE OFFER
SUCH NUMBER OF PREFERENCE SHARES (AS DEFINED HEREIN) THAT WOULD CONSTITUTE AT
LEAST 66 2/3% OF ALL OUTSTANDING PREFERENCE SHARES, (iii) ANY WAITING PERIOD
UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF 1976, AS AMENDED,
AND THE REGULATIONS THEREUNDER APPLICABLE TO THE PURCHASE OF SHARES PURSUANT
TO THE OFFER HAVING BEEN EXPIRED OR TERMINATED AND (iv) ALL CONSENTS,
APPROVALS, ORDERS OR AUTHORIZATIONS OF, OR REGISTRATIONS, DECLARATIONS OR
FILINGS WITH ANY GOVERNMENTAL AUTHORITY REQUIRED OR NECESSARY IN CONNECTION
WITH THE OFFER, THE MERGER AND THE MERGER AGREEMENT REFERRED TO HEREIN AND THE
TRANSACTIONS CONTEMPLATED BY THE MERGER AGREEMENT SHALL HAVE BEEN OBTAINED AND
SHALL BE IN FULL FORCE AND EFFECT.
                                ---------------
 
                                   IMPORTANT
  Any stockholder desiring to tender all or any portion of such stockholder's
Shares should either (i) complete and sign the Letter of Transmittal (or a fax
thereof) in accordance with the instructions in the Letter of Transmittal,
have such stockholder's signature thereon guaranteed if required by
Instruction 1 to the Letter of Transmittal, mail or deliver the Letter of
Transmittal (or such fax), or, in the case of a book-entry transfer effected
pursuant to the procedure set forth in Section 2, an Agent's Message (as
defined herein), and any other required documents to the Depositary and either
deliver the certificates for such Shares to the Depositary along with the
Letter of Transmittal (or fax) or deliver such Shares pursuant to the
procedure for book-entry transfer set forth in Section 2 or (ii) request such
stockholder's broker, dealer, bank, trust company or other nominee to effect
the transaction for such stockholder. A stockholder having Shares registered
in the name of a broker, dealer, bank, trust company or other nominee must
contact such broker, dealer, bank, trust company or other nominee if such
stockholder desires to tender such Shares.
  If a stockholder desires to tender Shares and such stockholder's
certificates for Shares are not immediately available or the procedure for
book-entry transfer cannot be completed on a timely basis, or time will not
permit all required documents to reach the Depositary prior to the expiration
of the Offer, such stockholder's tender may be effected by following the
procedure for guaranteed delivery set forth in Section 2.
  Questions and requests for assistance or for additional copies of this Offer
to Purchase, the Letter of Transmittal and the Notice of Guaranteed Delivery
may be directed to the Information Agent or to the Dealer Manager at their
respective addresses and telephone numbers set forth on the back cover of this
Offer to Purchase.
                                ---------------
                     The Dealer Manager for the Offer is:
                     MCFARLAND DEWEY SECURITIES CO., L.P.
January 16, 1998

 
To the Holders of Common Stock and $1.85 Cumulative Convertible Preference
 Stock of Bird Corporation:
 
                                 INTRODUCTION
 
  BI Expansion II Corp., a Massachusetts corporation (the "Purchaser") and a
wholly owned subsidiary of CertainTeed Corporation, a Delaware corporation
("CertainTeed") which is an indirect wholly owned subsidiary of Compagnie de
Saint-Gobain, a French corporation ("Saint-Gobain"), hereby offers to purchase
all outstanding shares of Common Stock, par value $1.00 per share (the "Common
Shares"), of Bird Corporation, a Massachusetts corporation (the "Company"), at
$5.50 per Common Share (the "Common Price") and hereby offers to purchase all
outstanding shares of $1.85 Cumulative Convertible Preference Stock, par value
$1.00 per share (the "Preference Shares"), of the Company at $20, which amount
shall not be adjusted for any dividends accrued and unpaid through the
Expiration Date (as defined herein), per Preference Share (the "Preference
Price"), in each case net to the seller in cash, without interest thereon,
upon the terms and subject to the conditions set forth in this Offer to
Purchase and in the related Letter of Transmittal (which, together with any
amendments or supplements hereto or thereto, collectively constitute the
"Offer"). The Common Shares and the Preference Shares are collectively
sometimes referred to as "Shares".
 
  Tendering stockholders will not be obligated to pay brokerage fees or
commissions or, except as set forth in Instruction 6 of the Letter of
Transmittal, transfer taxes on the purchase of Shares pursuant to the Offer.
The Purchaser will pay all fees and expenses of McFarland Dewey Securities
Co., L.P. ("McFarland Dewey"), which is acting as Dealer Manager (the "Dealer
Manager"), ChaseMellon Shareholder Services, L.L.C., which is acting as the
Depositary (the "Depositary"), and Georgeson & Company Inc., which is acting
as Information Agent (the "Information Agent"), incurred in connection with
the Offer. See Section 16.
 
  THE BOARD OF DIRECTORS OF THE COMPANY (THE "BOARD") HAS UNANIMOUSLY APPROVED
THE OFFER AND THE MERGER (AS DEFINED BELOW) AND DETERMINED THAT THE TERMS OF
THE OFFER AND THE MERGER ARE FAIR TO, AND IN THE BEST INTERESTS OF, THE
COMPANY'S STOCKHOLDERS AND RECOMMENDS THAT THE COMPANY'S STOCKHOLDERS ACCEPT
THE OFFER AND TENDER THEIR SHARES PURSUANT TO THE OFFER. THE FACTORS
CONSIDERED BY THE BOARD OF DIRECTORS OF THE COMPANY IN ARRIVING AT ITS
DECISION TO APPROVE THE OFFER AND THE MERGER AND TO RECOMMEND THAT
STOCKHOLDERS OF THE COMPANY ACCEPT THE OFFER AND TENDER THEIR SHARES ARE
DESCRIBED IN THE COMPANY'S SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE
14D-9 (THE "SCHEDULE 14D-9"), WHICH IS BEING MAILED TO STOCKHOLDERS OF THE
COMPANY HEREWITH. EACH OF THE DIRECTORS OF THE COMPANY HAS AGREED TO TENDER
HIS COMMON SHARES AND PREFERENCE SHARES INTO THE OFFER; SUCH SHARES REPRESENT
APPROXIMATELY 40.2% OF THE COMMON SHARES AND 16.2% OF THE PREFERENCE SHARES.
 
  THE COMPANY'S FINANCIAL ADVISOR, LEHMAN BROTHERS, HAS DELIVERED ITS OPINION
DATED JANUARY 12, 1998 THAT, AS OF SUCH DATE, AND SUBJECT TO THE CONDITIONS
AND LIMITATIONS SET FORTH THEREIN, THE CONSIDERATION TO BE RECEIVED BY HOLDERS
OF SHARES IN THE OFFER AND THE MERGER IS FAIR, FROM A FINANCIAL POINT OF VIEW.
SUCH OPINION IS SET FORTH IN FULL AS AN ANNEX TO THE SCHEDULE 14D-9.
 
  THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, (I) THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE OFFER SUCH NUMBER OF
COMMON SHARES THAT WOULD CONSTITUTE AT LEAST 66 2/3% OF ALL OUTSTANDING COMMON
SHARES (DETERMINED ON A FULLY DILUTED BASIS ON THE EXPIRATION DATE), (II)
THERE BEING VALIDLY TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE
OFFER SUCH NUMBER OF PREFERENCE SHARES THAT WOULD CONSTITUTE AT LEAST 66 2/3%
OF ALL OUTSTANDING PREFERENCE SHARES (CLAUSES (I) AND (II) TOGETHER BEING THE
"MINIMUM CONDITION"), (III) ANY WAITING PERIOD UNDER THE HART-SCOTT-RODINO
ANTITRUST IMPROVEMENTS ACT OF 1976, AS AMENDED, AND THE REGULATIONS THEREUNDER
(THE "HSR ACT") APPLICABLE TO THE PURCHASE OF SHARES PURSUANT TO THE OFFER
HAVING EXPIRED OR BEEN TERMINATED (THE "HSR CONDITION") AND (IV) ALL CONSENTS,
APPROVALS, ORDERS OR AUTHORIZATIONS OF, OR REGISTRATIONS, DECLARATIONS OR
FILINGS WITH, ANY GOVERNMENTAL AUTHORITY REQUIRED OR NECESSARY IN CONNECTION
WITH THE OFFER, THE MERGER AND THE MERGER AGREEMENT REFERRED TO HEREIN AND THE
TRANSACTIONS CONTEMPLATED BY THE MERGER AGREEMENT SHALL HAVE BEEN OBTAINED AND
SHALL BE IN FULL FORCE AND EFFECT (THE "REQUIRED CONSENTS CONDITION"). THE
PURCHASER RESERVES THE RIGHT (SUBJECT TO OBTAINING THE CONSENT OF THE COMPANY,
IF REQUIRED, AND THE APPLICABLE RULES AND REGULATIONS OF THE SECURITIES AND
EXCHANGE COMMISSION (THE
 
                                       1

 
"SEC")) TO WAIVE OR REDUCE THE MINIMUM CONDITION AND TO ELECT TO PURCHASE,
PURSUANT TO THE OFFER, FEWER THAN THE MINIMUM NUMBER OF SHARES NECESSARY TO
SATISFY THE MINIMUM CONDITION. THE PURCHASER CURRENTLY DOES NOT INTEND TO
WAIVE THE MINIMUM CONDITION. SEE SECTIONS 1 AND 14.
 
  The Company has informed the Purchaser that, as of December 31, 1997, there
were 4,159,877 Common Shares outstanding, 497,200 Common Shares authorized for
issuance pursuant to the exercise of outstanding options to purchase Common
Shares ("Stock Options"), 731,955 Common Shares authorized for issuance
pursuant to conversion of the Preference Shares at $22.25 per Common Share
(which is substantially above the Common Price) and 814,300 Preference Shares
outstanding. For purposes of the Offer, Common Shares outstanding on a fully
diluted basis will not include Common Shares issuable upon conversion of
Preference Shares that have been validly tendered and not withdrawn prior to
the Expiration Date or issuable upon the exercise of any Stock Options to the
extent holders of such Stock Options have agreed not to exercise such Stock
Options as long as the Merger Agreement is in effect. Based upon the
foregoing, the Purchaser believes that approximately 2,898,000 Common Shares
(assuming all Preference Shares are so validly tendered and not withdrawn and
all holders of Stock Options with an exercise price above the Common Price so
agree) or approximately 3,593,000 Common Shares (assuming conversion of all
outstanding Preference Shares and exercise of all outstanding Stock Options)
and approximately 542,900 Preference Shares (assuming no conversion or
redemption of any Preference Shares) must be validly tendered and not properly
withdrawn prior to the Expiration Date in order for the Minimum Condition to
be satisfied. See Section 1.
 
  The Offer is being made pursuant to the Agreement and Plan of Merger dated
as of January 12, 1998 (the "Merger Agreement"), among CertainTeed, the
Purchaser and the Company pursuant to which, as soon as practicable following
the consummation of the Offer and the satisfaction or waiver of certain
conditions, including approval of the Merger Agreement by the Company's
stockholders, the Purchaser will be merged with and into the Company (the
"Merger"), with the Company (the "Surviving Corporation") surviving the Merger
as a wholly owned subsidiary of CertainTeed. In the Merger, each outstanding
Share (other than Shares held by stockholders who perfect their appraisal
rights under Massachusetts law, Shares held in the Company's treasury and
Shares held directly by the Purchaser or CertainTeed) will be converted into
the right to receive $5.50 (in the case of Common Shares) and $20, which
amount shall not be adjusted for any dividends accrued and unpaid through the
effective date of the Merger (the "Effective Date") (in the case of Preference
Shares), in each case in cash, without interest. The Merger is subject to a
number of conditions, including the approval and adoption of the Merger
Agreement by stockholders of the Company. Under Massachusetts law, the
approval of the Board of Directors of the Company and the affirmative vote of
the holders of at least 66 2/3% of the issued and outstanding Common Shares
and the affirmative vote of at least 66 2/3% of the issued and outstanding
Preference Shares, each voting as a separate class, are required to approve
and adopt the Merger Agreement. Accordingly, if the Minimum Condition is
satisfied, the Purchaser will have sufficient voting power to cause the
approval and adoption of the Merger Agreement and the transactions
contemplated thereby without the affirmative vote of any other stockholder.
See Section 12.
 
  Certain Federal income tax consequences of the sale of Shares pursuant to
the Offer are described in Section 5.
 
  THIS OFFER TO PURCHASE AND THE RELATED LETTER OF TRANSMITTAL CONTAIN
IMPORTANT INFORMATION THAT SHOULD BE READ BEFORE ANY DECISION IS MADE WITH
RESPECT TO THE OFFER.
 
                               THE TENDER OFFER
 
1. TERMS OF THE OFFER
 
  Upon the terms and subject to the conditions of the Offer, the Purchaser
will accept for payment and pay for all Shares validly tendered prior to the
Expiration Date and not theretofore withdrawn in accordance with Section 3.
The term "Expiration Date" means 12:00 Midnight, New York City time, on
Friday, February 13, 1998, unless and until the Purchaser shall have extended
the period of time during which the Offer is open, in which event the term
"Expiration Date" shall mean the latest time and date at which the Offer, as
so extended by the Purchaser, will expire.
 
                                       2

 
  In the Merger Agreement, the Purchaser has agreed that it will not, without
the consent of the Company, waive the Minimum Condition. The Purchaser
expressly reserves the right to modify the terms of the Offer, except that,
without the consent of the Company, the Purchaser shall not (a) reduce the
number of Shares to be purchased in the Offer, (b) reduce the Common Price or
the Preference Price, (c) modify or add to the conditions to the Offer, (d)
except as provided in the next paragraph, extend the Offer, (e) change the
form of consideration payable in the Offer or (f) amend any other term of the
Offer in any manner adverse in any material respect to the holders of Shares.
 
  Notwithstanding the foregoing, the Purchaser may, without the consent of the
Company, (a) extend the Offer beyond any scheduled Expiration Date for a
period not to exceed 20 business days, if at such scheduled Expiration Date,
any of the conditions to the Purchaser's obligation to accept for payment, and
pay for, Common Shares or Preference Shares are not satisfied or waived, until
such time as such conditions are satisfied or waived, (b) extend the Offer for
any period required by any rule, regulation, interpretation or position of the
SEC or the staff thereof applicable to the Offer and (c) terminate the Offer
if permitted by the Merger Agreement without prejudice to any of its and
CertainTeed's rights under the Merger Agreement, including to proceed with the
Merger in accordance with, and subject to the terms and conditions of, the
Merger Agreement. As used in this Offer to Purchase, "business day" has the
meaning set forth in Rule 14d-1 under the Securities Exchange Act of 1934 (the
"Exchange Act").
 
  Subject to the terms of the Merger Agreement and applicable rules and
regulations of the SEC, the Purchaser reserves the right, in its sole
discretion, at any time and from time to time, and regardless of whether or
not any of the events or facts set forth in Section 14 hereof shall have
occurred, to (a) extend the period of time during which the Offer is open for
a period not to exceed 20 business days, and thereby delay acceptance for
payment of and the payment for any Shares, by giving oral or written notice of
such extension to the Depositary and (b) except as set forth above, amend the
Offer in any other respect by giving oral or written notice of such amendment
to the Depositary. UNDER NO CIRCUMSTANCES WILL INTEREST BE PAID ON THE
PURCHASE PRICE FOR TENDERED SHARES, WHETHER OR NOT THE PURCHASER EXERCISES ITS
RIGHT TO EXTEND THE OFFER.
 
  If by 12:00 Midnight, New York City time, on Friday, February 13, 1998 (or
any date or time then set as the Expiration Date), any or all of the
conditions to the Offer have not been satisfied or waived, the Purchaser
reserves the right (but shall not be obligated), subject to the applicable
rules and regulations of the SEC, to (a) terminate the Offer and not accept
for payment or pay for any Shares and return all tendered Shares to tendering
stockholders, (b) except as set forth above with respect to the Minimum
Condition, waive all the unsatisfied conditions and accept for payment and pay
for all Shares validly tendered prior to the Expiration Date and not
theretofore withdrawn, (c) extend the Offer and, subject to the right of
stockholders to withdraw Shares until the Expiration Date, retain the Shares
that have been tendered during the period or periods for which the Offer is
extended or (d) amend the Offer.
 
  There can be no assurance that the Purchaser will exercise its right to
extend the Offer. Any extension, amendment or termination will be followed as
promptly as practicable by public announcement. In the case of an extension,
Rule 14e-l(d) under the Exchange Act requires that the announcement be issued
no later than 9:00 a.m., New York City time, on the next business day after
the previously scheduled Expiration Date in accordance with the public
announcement requirements of Rule 14d-4(c) under the Exchange Act. Subject to
applicable law (including Rules 14d-4(c) and 14d-6(d) under the Exchange Act,
which require that any material change in the information published, sent or
given to stockholders in connection with the Offer be promptly disseminated to
stockholders in a manner reasonably designed to inform stockholders of such
change), and without limiting the manner in which the Purchaser may choose to
make any public announcement, the Purchaser will not have any obligation to
publish, advertise or otherwise communicate any such public announcement other
than by making a release to the Dow Jones News Service.
 
  If the Purchaser extends the Offer or if the Purchaser is delayed in its
acceptance for payment of or payment for Shares (whether before or after its
acceptance for payment of Shares) or it is unable to pay for Shares pursuant
to the Offer for any reason, then, without prejudice to the Purchaser's rights
under the Offer, the Depositary may
 
                                       3

 
retain tendered Shares on behalf of the Purchaser, and such Shares may not be
withdrawn except to the extent tendering stockholders are entitled to
withdrawal rights as described in Section 3. However, the ability of the
Purchaser to delay payment for Shares that the Purchaser has accepted for
payment is limited by Rule 14e-1(c) under the Exchange Act, which requires
that a bidder pay the consideration offered or return the securities deposited
by or on behalf of holders of securities promptly after the termination or
withdrawal of such bidder's offer, and by the terms of the Merger Agreement,
which require that Purchaser pay for Shares accepted for payment as soon as
practicable after the Expiration Date.
 
  If the Purchaser makes a material change in the terms of the Offer or the
information concerning the Offer or waives a material condition of the Offer
(including a waiver of the Minimum Condition), the Purchaser will disseminate
additional tender offer materials and extend the Offer to the extent required
by Rules 14d-4(c), 14d-6(d) and 14e-1 under the Exchange Act. The minimum
period during which an offer must remain open following material changes in
the terms of the Offer or information concerning the Offer, other than a
change in price or a change in the percentage of securities sought, will
depend upon the facts and circumstances then existing, including the relative
materiality of the changed terms or information. With respect to a change in
price or a change in the percentage of securities sought, a minimum period of
10 business days is generally required to allow for adequate dissemination to
stockholders.
 
  The Company has provided the Purchaser with the Company's stockholder lists
and security position listings for the purpose of disseminating the Offer to
holders of Shares. This Offer to Purchase, the related Letter of Transmittal
and other relevant materials will be mailed by the Purchaser to record holders
of Shares and will be furnished to brokers, dealers, banks, trust companies
and similar persons whose names, or the names of whose nominees, appear on the
stockholder lists, or, if applicable, who are listed as participants in a
clearing agency's security position listing, for subsequent transmittal to
beneficial owners of Shares.
 
2. PROCEDURE FOR TENDERING SHARES AND RIGHTS
 
  Valid Tender. For a stockholder validly to tender Shares pursuant to the
Offer, either (a) a properly completed and duly executed Letter of Transmittal
(or fax thereof), together with any required signature guarantees and any
other required documents, must be received by the Depositary at one of its
addresses set forth on the back cover of this Offer to Purchase prior to the
Expiration Date and either certificates for tendered Shares must be received
by the Depositary at one of such addresses or such Shares must be delivered
pursuant to the procedures for book-entry transfer set forth below (and a
confirmation of such delivery, including an Agent's Message (as defined
below), must be received by the Depositary), in each case prior to the
Expiration Date or (b) the tendering stockholder must comply with the
guaranteed delivery procedures set forth below.
 
  The Depositary will establish accounts with respect to the Shares at The
Depositary Trust Company and Philadelphia Depositary Trust Company (the "Book-
Entry Transfer Facilities") for purposes of the Offer within two business days
after the date of this Offer to Purchase. Any financial institution that is a
participant in any of the Book-Entry Transfer Facilities' systems may make
book-entry delivery of Shares by causing a Book-Entry Transfer Facility to
transfer such Shares into the Depositary's account in accordance with such
Book-Entry Transfer Facility's procedures for such transfer. However, although
delivery of Shares may be effected through book-entry transfer into the
Depositary's account at a Book-Entry Transfer Facility, the Letter of
Transmittal (or fax thereof), properly completed and duly executed, with any
required signature guarantees, or an Agent's Message, and any other required
documents, must, in any case, be transmitted to, and received by, the
Depositary at one of its addresses set forth on the back cover of this Offer
to Purchase prior to the Expiration Date, or the tendering stockholder must
comply with the guaranteed delivery procedures described below. The
confirmation of a book-entry transfer of Shares into the Depositary's account
at a Book-Entry Transfer Facility as described above is referred to herein as
a "Book-Entry Confirmation." DELIVERY OF DOCUMENTS TO A BOOK-ENTRY TRANSFER
FACILITY IN ACCORDANCE WITH SUCH BOOK-ENTRY TRANSFER FACILITY'S PROCEDURES
DOES NOT CONSTITUTE DELIVERY TO THE DEPOSITARY.
 
 
                                       4

 
  The term "Agent's Message" means a message transmitted by a Book-Entry
Transfer Facility to, and received by, the Depositary and forming a part of a
Book-Entry Confirmation, which states that such Book-Entry Transfer Facility
has received an express acknowledgement from the participant in such Book-
Entry Transfer Facility tendering the Shares that such participant has
received and agrees to be bound by the terms of the Letter of Transmittal and
that the Purchaser may enforce such agreement against the participant.
 
  THE METHOD OF DELIVERY OF SHARES, THE LETTER OF TRANSMITTAL AND ALL OTHER
REQUIRED DOCUMENTS, INCLUDING DELIVERY THROUGH ANY BOOK-ENTRY TRANSFER
FACILITY, IS AT THE ELECTION AND RISK OF THE TENDERING STOCKHOLDER. SHARES
WILL BE DEEMED DELIVERED ONLY WHEN ACTUALLY RECEIVED BY THE DEPOSITARY
(INCLUDING, IN THE CASE OF A BOOK-ENTRY TRANSFER, BY BOOK-ENTRY CONFIRMATION).
IF DELIVERY IS BY MAIL, REGISTERED MAIL WITH RETURN RECEIPT REQUESTED,
PROPERLY INSURED, IS RECOMMENDED. IN ALL CASES, SUFFICIENT TIME SHOULD BE
ALLOWED TO ENSURE TIMELY DELIVERY.
 
  Signature Guarantees. No signature guarantee is required on the Letter of
Transmittal (a) if the Letter of Transmittal is signed by the registered
holder(s) (which term, for purposes of this Section, includes any participant
in any of the Book-Entry Transfer Facilities' systems whose name appears on a
security position listing as the owner of the Shares) of such Shares tendered
therewith and such registered holder has not completed either the box entitled
"Special Delivery Instructions" or the box entitled "Special Payment
Instructions" on the Letter of Transmittal or (b) if such Shares are tendered
for the account of a financial institution (including most commercial banks,
savings and loan associations and brokerage houses) that is a member firm of a
national securities exchange registered with the SEC or of the National
Association of Securities Dealers, Inc. (the "NASD"), or a commercial bank or
trust company having an office or correspondent in the United States (an
"Eligible Institution"). In all other cases, all signatures on the Letter of
Transmittal must be guaranteed by an Eligible Institution. See Instructions 1
and 5 to the Letter of Transmittal. If the certificates for Shares are
registered in the name of a person other than the signer of the Letter of
Transmittal, or if payment is to be made or certificates for Shares not
tendered or not accepted for payment are to be returned to a person other than
the registered holder of the certificates surrendered, the tendered
certificates must be endorsed or accompanied by appropriate stock powers, in
either case signed exactly as the name or names of the registered holders or
owners appear on the certificates, with the signatures on the certificates or
stock powers guaranteed in the manner described above. See Instructions 1 and
5 to the Letter of Transmittal.
 
  Guaranteed Delivery. If a stockholder desires to tender Shares pursuant to
the Offer and such stockholder's certificates for Shares are not immediately
available or the procedure for book-entry transfer cannot be completed on a
timely basis or time will not permit all required documents to reach the
Depositary prior to the Expiration Date, such stockholder's tender may be
effected if all the following conditions are met:
 
    (i) such tender is made by or through an Eligible Institution;
 
    (ii) a properly completed and duly executed Notice of Guaranteed
  Delivery, substantially in the form provided by the Purchaser, is received
  by the Depositary, as provided below, prior to the Expiration Date; and
 
    (iii) the certificates for all tendered Shares, in proper form for
  transfer (or a Book-Entry Confirmation with respect to all such Shares),
  together with a properly completed and duly executed Letter of Transmittal
  (or fax), with any required signature guarantees, or, in the case of a
  book-entry transfer, an Agent's Message, and any other required documents
  are received by the Depositary within three trading days after the date of
  execution of such Notice of Guaranteed Delivery. A "trading day" is any day
  on which the Nasdaq National Market (the "Nasdaq National Market") operated
  by the NASD is open for business.
 
  The Notice of Guaranteed Delivery may be delivered by hand to the Depositary
or transmitted by telegram, fax or mail to the Depositary and must include a
guarantee by an Eligible Institution in the form set forth in such Notice of
Guaranteed Delivery.
 
  Notwithstanding any other provision hereof, payment for Shares accepted for
payment pursuant to the Offer will in all cases be made only after timely
receipt by the Depositary of (a) certificates for (or a timely Book-Entry
Confirmation with respect to such Shares) such Shares, (b) a Letter of
Transmittal (or fax), properly completed
 
                                       5

 
and duly executed, with any required signature guarantees, or, in the case of
a book-entry transfer, an Agent's Message, and (c) any other documents
required by the Letter of Transmittal. Accordingly, tendering stockholders may
be paid at different times depending upon when certificates for Shares or
Book-Entry Confirmations with respect to such Shares are actually received by
the Depositary. UNDER NO CIRCUMSTANCES WILL ANY INTEREST BE PAID ON THE
PURCHASE PRICE OF THE SHARES, REGARDLESS OF ANY EXTENSION OF THE OFFER OR ANY
DELAY IN MAKING SUCH PAYMENT.
 
  The valid tender of Shares pursuant to one of the procedures described above
will constitute a binding agreement between the tendering stockholder and the
Purchaser upon the terms and subject to the conditions of the Offer.
 
  Appointment. By executing a Letter of Transmittal as set forth above, the
tendering stockholder will irrevocably appoint designees of the Purchaser as
such stockholder's attorneys-in-fact and proxies in the manner set forth in
the Letter of Transmittal, each with full power of substitution, to the full
extent of such stockholder's rights with respect to the Shares tendered by
such stockholder and accepted for payment by the Purchaser and with respect to
any and all other Shares or other securities or rights issued or issuable in
respect of such Shares on or after January 12, 1998. All such proxies will be
considered coupled with an interest in the tendered Shares. Such appointment
will be effective when, and only to the extent that, the Purchaser accepts for
payment Shares tendered by such stockholder as provided herein. Upon such
appointment, all prior powers of attorney, proxies and consents given by such
stockholder with respect to such Shares or other securities or rights will,
without further action, be revoked and no subsequent powers of attorney,
proxies, consents or revocations may be given (and, if given, will not be
deemed effective). The designees of the Purchaser will thereby be empowered to
exercise all voting and other rights with respect to such Shares and other
securities or rights in respect of any annual, special or adjourned meeting of
the Company's stockholders, actions by written consent in lieu of any such
meeting or otherwise, as they in their sole discretion deem proper. The
Purchaser reserves the right to require that, in order for Shares to be deemed
validly tendered, immediately upon the Purchaser's acceptance for payment of
such Shares, the Purchaser must be able to exercise full voting, consent and
other rights with respect to such Shares and other securities or rights,
including voting at any meeting of stockholders.
 
  Determination of Validity. All questions as to the validity, form,
eligibility (including time of receipt) and acceptance of any tender of Shares
will be determined by the Purchaser in its sole discretion, which
determination will be final and binding. The Purchaser reserves the absolute
right to reject any or all tenders determined by it not to be in proper form
or the acceptance for payment of or payment for which may, in the opinion of
the Purchaser's counsel, be unlawful. The Purchaser also reserves the absolute
right to waive any defect or irregularity in the tender of any Shares of any
particular stockholder whether or not similar defects or irregularities are
waived in the case of other stockholders. No tender of Shares will be deemed
to have been validly made until all defects or irregularities relating thereto
have been cured or waived. None of the Purchaser, Saint-Gobain, CertainTeed,
the Depositary, the Information Agent, the Dealer Manager or any other person
will be under any duty to give notification of any defects or irregularities
in tenders or incur any liability for failure to give any such notification.
The Purchaser's interpretation of the terms and conditions of the Offer
(including the Letter of Transmittal and the instructions thereto) will be
final and binding.
 
  Backup Withholding. In order to avoid "backup withholding" of Federal income
tax on payments of cash pursuant to the Offer and/or the Merger, a stockholder
surrendering Shares in the Offer and/or the Merger must, unless an exemption
applies, provide the Depositary with such stockholder's correct taxpayer
identification number ("TIN") on a Substitute Form W-9 and certify under
penalties of perjury that such TIN is correct and that such stockholder is not
subject to backup withholding. If a stockholder does not provide such
stockholder's correct TIN or fails to provide the certifications described
above, the Internal Revenue Service (the "IRS") may impose a penalty on such
stockholder and payment of cash to such stockholder pursuant to the Offer, the
Merger and/or the redemption of Preference Shares may be subject to backup
withholding of 31%. All stockholders surrendering Shares pursuant to the Offer
and/or the Merger should complete and sign the Substitute Form W-9 included as
part of the Letter of Transmittal to provide the information and certification
necessary to avoid backup withholding (unless an applicable exemption exists
and is proved in a manner satisfactory to the
 
                                       6

 
Purchaser and the Depositary). Certain stockholders (including, among others,
all corporations and certain foreign individuals and entities) are not subject
to backup withholding. Noncorporate foreign stockholders should complete and
sign a Form W-8, Certificate of Foreign Status, a copy of which may be
obtained from the Depositary, in order to avoid backup withholding. See
Instruction 9 to the Letter of Transmittal.
 
3. WITHDRAWAL RIGHTS
 
  Except as otherwise provided in this Section 3, tenders of Shares are
irrevocable. Shares tendered pursuant to the Offer may be withdrawn pursuant
to the procedures set forth below at any time prior to the Expiration Date
and, unless theretofore accepted for payment and paid for by the Purchaser
pursuant to the Offer, may also be withdrawn at any time after Monday, March
16, 1998.
 
  For a withdrawal to be effective, a written, telegraphic or faxed notice of
withdrawal must be timely received by the Depositary at one of its addresses
set forth on the back cover of this Offer to Purchase and must specify the
name of the person having tendered the Shares to be withdrawn, the number of
Shares to be withdrawn and the name of the registered holder of the Shares to
be withdrawn, if different from the name of the person who tendered the
Shares. If certificates for Shares have been delivered or otherwise identified
to the Depositary, then, prior to the physical release of such certificates,
the serial numbers shown on such certificates must be submitted to the
Depositary and, unless such Shares have been tendered by an Eligible
Institution, the signatures on the notice of withdrawal must be guaranteed by
an Eligible Institution. If Shares have been delivered pursuant to the
procedure for book-entry transfer as set forth in Section 2, any notice of
withdrawal must also specify the name and number of the account at the
appropriate Book-Entry Transfer Facility to be credited with the withdrawn
Shares and otherwise comply with such Book-Entry Transfer Facility's
procedures. Withdrawals of tenders of Shares may not be rescinded, and any
Shares properly withdrawn will thereafter be deemed not validly tendered for
purposes of the Offer. However, withdrawn Shares may be retendered by again
following one of the procedures described in Section 2 at any time prior to
the Expiration Date.
 
  All questions as to the form and validity (including time of receipt) of
notices of withdrawal will be determined by the Purchaser in its sole
discretion, which determination will be final and binding. None of the
Purchaser, Saint-Gobain, CertainTeed, the Depositary, the Information Agent,
the Dealer Manager or any other person will be under any duty to give
notification of any defects or irregularities in any notice of withdrawal or
incur any liability for failure to give any such notification.
 
4. ACCEPTANCE FOR PAYMENT AND PAYMENT
 
  Upon the terms and subject to the conditions of the Offer (including, if the
Offer is extended or amended, the terms and conditions of any such extension
or amendment), the Purchaser will accept for payment and will pay for all
Shares validly tendered prior to the Expiration Date, and not properly
withdrawn in accordance with Section 3, promptly after the Expiration Date.
All questions as to the satisfaction of such terms and conditions will be
determined by the Purchaser in its sole discretion, which determination will
be final and binding. See Sections 1 and 14. The Purchaser expressly reserves
the right, in its sole discretion, to delay acceptance for payment of or
payment for Shares in order to comply in whole or in part with any applicable
law, including, without limitation, the HSR Act. Any such delays will be
effected in compliance with Rule 14e-l(c) under the Exchange Act, which
requires that a tender offeror pay the consideration offered or return the
tendered securities promptly after termination or withdrawal of a tender
offer.
 
  Saint-Gobain filed a Notification and Report Form with respect to the Offer
under the HSR Act on
January 15, 1998. The waiting period under the HSR Act with respect to the
Offer will expire at 11:59 p.m., New York City time, on January 30, 1998,
unless early termination of the waiting period is granted. However, the
Antitrust Division of the Department of Justice (the "Antitrust Division") or
the Federal Trade Commission (the "FTC") may extend the waiting period by
requesting additional information or documentary material from Saint-Gobain.
If such a request is made, such waiting period will expire at 11:59 p.m., New
York City time, on the 10th day after substantial compliance by Saint-Gobain
with such request. See Section 15 hereof for additional information concerning
the HSR Act and the applicability of the antitrust laws to the Offer.
 
                                       7

 
  In all cases, payment for Shares accepted for payment pursuant to the Offer
will be made only after timely receipt by the Depositary of (a) certificates
for (or a timely Book-Entry Confirmation with respect to) such Shares, (b) a
Letter of Transmittal (or fax thereof), properly completed and duly executed,
with any required signature guarantees, or, in the case of a book-entry
transfer, an Agent's Message, and (c) any other documents required by the
Letter of Transmittal. The per Common Share consideration and the per
Preference Share consideration paid to any stockholder pursuant to the Offer
will be the highest per Common Share consideration and per Preference Share
consideration, respectively, paid to any other holder of Common Shares or
Preference Shares, as the case may be, pursuant to the Offer.
 
  For purposes of the Offer, the Purchaser will be deemed to have accepted for
payment, and thereby purchased, Shares properly tendered to the Purchaser and
not withdrawn as, if and when the Purchaser gives oral or written notice to
the Depositary of the Purchaser's acceptance for payment of such Shares.
Payment for Shares accepted for payment pursuant to the Offer will be made by
deposit of the purchase price therefor with the Depositary, which will act as
agent for tendering stockholders for the purpose of receiving payment from the
Purchaser and transmitting payment to tendering stockholders. UNDER NO
CIRCUMSTANCES WILL INTEREST BE PAID ON THE PURCHASE PRICE OF ANY SHARES TO BE
PAID BY THE PURCHASER, REGARDLESS OF ANY EXTENSION OF THE OFFER OR ANY DELAY
IN MAKING SUCH PAYMENT.
 
  If the Purchaser is delayed in its acceptance for payment of or payment for
Shares or is unable to accept for payment or pay for Shares pursuant to the
Offer for any reason, then, without prejudice to the Purchaser's rights under
the Offer (but subject to compliance with Rule 14e-1(c) under the Exchange
Act, which requires that a tender offeror pay the consideration offered or
return the tendered securities promptly after termination or withdrawal of a
tender offer, and the terms of the Merger Agreement), the Depositary may,
nevertheless, on behalf of the Purchaser, retain tendered Shares, and such
Shares, may not be withdrawn except to the extent tendering stockholders are
entitled to exercise, and duly exercise, withdrawal rights as described in
Section 3.
 
  If any tendered Shares are not purchased pursuant to the Offer for any
reason, certificates for any such Shares will be returned without expense to
the tendering stockholder (or, in the case of Shares delivered by book-entry
transfer of such Shares into the Depositary's account at a Book-Entry Transfer
Facility pursuant to the procedure set forth in Section 2, such Shares will be
credited to an account maintained at the appropriate Book-Entry Transfer
Facility) as promptly as practicable after the expiration or termination of
the Offer.
 
  The Purchaser reserves the right to transfer or assign, in whole or from
time to time in part, to Saint-Gobain, or to one or more direct or indirect
wholly owned subsidiaries of Saint-Gobain, the right to purchase Shares
tendered pursuant to the Offer, but any such transfer or assignment will not
relieve the Purchaser of its obligations under the Offer and will in no way
prejudice the rights of tendering stockholders to receive payment for Shares
validly tendered and accepted for payment pursuant to the Offer.
 
5. CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
  The transfer of Shares pursuant to the Offer or the Merger will be a taxable
transaction for Federal income tax purposes under the Internal Revenue Code of
1986, as amended (the "Code"), and may also be a taxable transaction under
applicable state, local or foreign income or other tax laws. Generally, for
Federal income tax purposes, a stockholder will recognize gain or loss equal
to the difference between the amount of cash received by the stockholder
pursuant to the Offer or the Merger and the aggregate tax basis in the Shares
purchased pursuant to the Offer or the Merger, as the case may be. Gain or
loss will be calculated separately for each block of Shares tendered and
purchased pursuant to the Offer or in the Merger, as the case may be.
 
  Gain (or loss) will be capital gain (or loss), assuming that such Shares are
held as a capital asset. Capital gains of individuals, estates and trusts
generally are subject to a maximum Federal income tax rate of (i) 39.6% if, at
the time the Company accepts the Shares for payment, the shareholder held the
Shares for not more than one year, (ii) 28% if the shareholder held such
Shares for more than one year but not more than 18 months at such time and
(iii) 20% if the shareholder held such Shares for more than 18 months at such
time. Capital gains of corporations generally are taxed at the Federal income
tax rates applicable to corporate ordinary income. In addition, under present
law, the ability to use capital losses to offset ordinary income is limited.
 
                                       8

 
  A stockholder that tenders Shares pursuant to the Offer or surrenders Shares
pursuant to the Merger may be subject to 31% backup withholding unless the
stockholder provides its TIN and certifies that such number is correct or
properly certifies that it is awaiting a TIN, or unless an exemption applies.
A stockholder that does not furnish its TIN may be subject to a penalty
imposed by the IRS. See "--Backup Withholding" under Section 2.
 
  If backup withholding applies to a stockholder, the Depositary is required
to withhold 31% from payments to such stockholder. Backup withholding is not
an additional tax. Rather, the amount of the backup withholding can be
credited against the Federal income tax liability of the person subject to the
backup withholding, provided that the required information is given to the
IRS. If backup withholding results in an overpayment of tax, a refund can be
obtained by the stockholder upon filing an income tax return.
 
  THE FOREGOING DISCUSSION MAY NOT BE APPLICABLE WITH RESPECT TO COMMON SHARES
RECEIVED PURSUANT TO THE EXERCISE OF EMPLOYEE STOCK OPTIONS OR OTHERWISE AS
COMPENSATION OR WITH RESPECT TO HOLDERS OF SHARES WHO ARE SUBJECT TO SPECIAL
TAX TREATMENT UNDER THE CODE, SUCH AS NON-U.S. PERSONS, LIFE INSURANCE
COMPANIES, TAX-EXEMPT ORGANIZATIONS AND FINANCIAL INSTITUTIONS, AND MAY NOT
APPLY TO A HOLDER OF SHARES IN LIGHT OF INDIVIDUAL CIRCUMSTANCES. STOCKHOLDERS
ARE URGED TO CONSULT THEIR OWN TAX ADVISORS TO DETERMINE THE PARTICULAR TAX
CONSEQUENCES TO THEM (INCLUDING THE APPLICATION AND EFFECT OF ANY STATE, LOCAL
OR FOREIGN INCOME AND OTHER TAX LAWS) OF THE OFFER AND THE MERGER.
 
6. PRICE RANGE OF THE SHARES; DIVIDENDS ON THE COMMON SHARES AND PREFERENCE
SHARES
 
  The Common Shares are quoted on the Nasdaq National Market under the symbol
BIRD, and the Preference Shares are quoted on the Nasdaq SmallCap Market under
the symbol of BIRDP. The principal market for the Common Shares and Preference
Shares is the over-the-counter market.
 
  The following table sets forth, for each of the periods indicated, the range
of high and low last sales prices per Common Share.
 
                               BIRD CORPORATION
 


                                                 LAST SALES PRICES OF
                                                    COMMON SHARES
                                                 --------------------------
   CALENDAR YEAR                                    HIGH            LOW
   -------------                                 ----------      ----------
                                                           
   1996
     First Quarter.............................  $       7 5/8   $       4 1/8
     Second Quarter............................          7 1/2           3 1/4
     Third Quarter.............................          4 5/8           2 3/4
     Fourth Quarter............................          6               4 1/2
   1997
     First Quarter.............................          6 1/8           5 3/16
     Second Quarter............................          5 5/16          3 11/16
     Third Quarter.............................          5               3 5/8
     Fourth Quarter............................          4 5/8           3 31/32
   1998
     First Quarter (through January 12, 1998)..          4 5/8           4

 
  On January 12, 1998, the last full trading day before the first public
announcement of the execution of the Merger Agreement, the last reported sale
price of the Common Shares on the Nasdaq National Market was $4 3/8 per Common
Share. On January 15, 1998, the last full trading day before the commencement
of the Offer, the last reported sales price of the Common Shares on the Nasdaq
National Market was $5 13/32 per Common Share.
 
  The Company did not pay any cash dividends on the Common Shares in 1996 and
1997 and has not paid any cash dividends on the Common Shares in 1998 through
the date of this Offer to Purchase.
 
                                       9

 
  The following table sets forth, for each of the periods indicated, the range
of high and low ask and bid quotations for the Preference Shares.
 
                               BIRD CORPORATION
 


                          BID AND ASK PRICES OF PREFERENCE SHARES
                         ---------------------------------------------------------
CALENDAR YEAR             HIGH BID        LOW BID        HIGH ASK        LOW ASK
- -------------            ----------      ---------      ----------      ----------
                                                            
1996
  First Quarter.........   $      20 1/2   $  16      $      22      $      17 1/2
  Second Quarter........          21          12 1/2         22 1/2         13 1/2
  Third Quarter.........          14          12 3/4         15 1/2         14
  Fourth Quarter........          16 1/2      13             19 1/2         14
1997
  First Quarter.........          16 1/4      14 1/4         19             17
  Second Quarter........          16 1/4      16             19             19
  Third Quarter.........          16 1/2      15 1/4         19             17
  Fourth Quarter........          16 1/2      14             18 1/2         15
1998
  First Quarter (through
   January 12, 1998)....           14         14             17             17

 
  On January 12, 1998, the last full trading day before the public
announcement of the execution of the Merger Agreement, the last reported bid
quotation of the Preference Shares on the Nasdaq Small Cap Market was $14.00
per Preference Share. On January 15, 1998, the last full trading day before
the commencement of the Offer, the last reported bid quotation of the
Preference Shares on the Nasdaq SmallCap Market was $19.00 per Preference
Share.
 
  Dividend payments, if declared, on the Preference Shares are made on
February 15, May 15, August 15 and November 15 of each year. The Company is
currently in arrears with respect to five dividend payments. In light of the
Offer, the Company does not intend to pay any dividend on the Preference
Shares on February 15, 1998. The aggregate amount of accrued and unpaid
dividends on the Preference Shares was $2.31 per Preference Share as of
November 15, 1997 and through February 13, 1998 will include an additional
$0.45 per Preference Share, and, after February 13, 1998, dividends on each
Preference Share will accrue at a rate of $0.0051 per day per Preference
Share.
 
  STOCKHOLDERS ARE URGED TO OBTAIN CURRENT MARKET QUOTATIONS FOR THE COMMON
SHARES AND PREFERENCE SHARES.
 
7. EFFECT OF THE OFFER ON THE MARKET FOR THE COMMON SHARES AND PREFERENCE
   SHARES; STOCK QUOTATION; EXCHANGE ACT REGISTRATION; MARGIN REGULATIONS
 
  Market for the Shares. The purchase of Shares pursuant to the Offer will
reduce the number of holders of Shares and the number of Shares that might
otherwise trade publicly and could adversely affect the liquidity and market
value of the remaining Shares held by the public.
 
 Stock Quotation.
 
  (1) Common Shares. Depending upon the number of Common Shares purchased
pursuant to the Offer, the Common Shares may no longer meet the requirements
of the NASD for continued inclusion in the Nasdaq National Market, which among
other things require that an issuer have at least 200,000 publicly held
shares, held by at least 400 stockholders or 300 stockholders of round lots,
with a market value of at least $1,000,000, and have net tangible assets of at
least $1,000,000, $2,000,000 or $4,000,000 depending on profitability levels
during the issuer's four most recent fiscal years. If these standards are not
met, the Common Shares might
 
                                      10

 
nevertheless continue to be included in the NASD's Nasdaq Stock Market (the
"Nasdaq Stock Market") with quotations published in the Nasdaq "additional
list" or in one of the "local lists", but if the number of holders of the
Common Shares were to fall below 300, or if the number of publicly held Common
Shares were to fall below 100,000 or there were not at least two registered
and active market makers for the Common Shares, the NASD's rules provide that
the Common Shares would no longer be "qualified" for Nasdaq Stock Market
reporting and the Nasdaq Stock Market would cease to provide any quotations.
Common Shares held directly or indirectly by directors, officers or beneficial
owners of more than 10% of the Common Shares are not considered as being
publicly held for this purpose. According to the Company, as of December 31,
1997, there were approximately 2,000 holders of record of Common Shares and
there were 4,159,877 Common Shares outstanding. If, as a result of the
purchase of Common Shares pursuant to the Offer or otherwise, the Common
Shares no longer meet the requirements of the NASD for continued inclusion in
the Nasdaq National Market or in any other tier of the Nasdaq Stock Market and
the Common Shares are no longer included in the Nasdaq National Market or in
any other tier of the Nasdaq Stock Market, as the case may be, the market for
Common Shares could be adversely affected.
 
  In the event that the Common Shares no longer meet the requirements of the
NASD for continued inclusion in any tier of the Nasdaq Stock Market, it is
possible that the Common Shares would continue to trade in the over-the-
counter market and that price quotations would be reported by other sources.
The extent of the public market for the Common Shares and the availability of
such quotations would, however, depend upon the number of holders of Common
Shares remaining at such time, the interests in maintaining a market in Common
Shares on the part of securities firms, the possible termination of
registration of the Common Shares under the Exchange Act, as described below,
and other factors.
 
  (2) Preference Shares. After the Offer, the reduced number of Preference
Shares available for trading may cause the Preference Shares to no longer meet
an additional qualification requirement of the NASD for continued inclusion in
the Nasdaq Stock Market that the issue have at least two registered and active
market makers. Accordingly, after the Offer, the Nasdaq Stock Market may cease
to provide any quotations. According to the Company, as of December 31, 1997,
there were approximately 130 holders of record of Preference Shares and
814,300 Preference Shares outstanding. Although Preference Shares have never
been registered under Section 12 of the Exchange Act and, as a result, do not
meet the qualification requirements of the NASD for inclusion in the Nasdaq
Stock Market, to date the Preference Shares have been so included.
 
 Exchange Act Registration.
 
  The Common Shares are currently registered under Section 12(g) of the
Exchange Act. Registration of the Common Shares under the Exchange Act may be
terminated upon application of the Company to the SEC if the Common Shares are
not listed on a national securities exchange, quoted on an automated inter-
dealer quotation system or held by 300 or more holders of record. Termination
of registration of the Common Shares under the Exchange Act would
substantially reduce the information required to be furnished by the Company
to its stockholders and to the SEC and would make certain provisions of the
Exchange Act no longer applicable to the Company, such as the short-swing
profit recovery provisions of Section 16(b) of the Exchange Act, the
requirement of furnishing a proxy statement pursuant to Section 14(a) of the
Exchange Act in connection with stockholders' meetings and the related
requirement of furnishing an annual report to stockholders and the
requirements of Rule 13e-3 under the Exchange Act with respect to "going
private" transactions. Furthermore, the ability of "affiliates" of the Company
and persons holding "restricted securities" of the Company to dispose of such
securities pursuant to Rule 144 or 144A promulgated under the Securities Act
of 1933, may be impaired or eliminated. The Purchaser intends to seek to cause
the Company to apply for termination of registration of the Common Shares
under the Exchange Act as soon after the completion of the Offer as the
requirements for such termination are met.
 
  If public quotation and registration of the Common Shares and the Preference
Shares is not terminated prior to the Merger, then the Common Shares and the
Preference Shares will no longer be quoted and the registration of the Common
Shares under the Exchange Act will be terminated following the consummation of
the Merger.
 
 
                                      11

 
 Margin Regulations.
 
  (1) Common Shares. The Common Shares are currently "margin securities" under
the regulations of the Board of Governors of the Federal Reserve System (the
"Federal Reserve Board"), which has the effect, among other things, of
allowing brokers to extend credit on the collateral of the Common Shares.
Depending upon factors similar to those described above regarding listing and
market quotations, it is possible that, following the Offer, the Common Shares
would no longer constitute "margin securities" for the purposes of the margin
regulations of the Federal Reserve Board and therefore could no longer be used
as collateral for loans made by brokers. In any event, the Common Shares will
cease to be "margin securities" if registration of the Common Shares under the
Exchange Act is terminated.
 
  (2) Preference Shares. The Preference Shares are not currently margin
securities.
 
8. CERTAIN INFORMATION CONCERNING THE COMPANY
 
  The Company is a Massachusetts corporation with its principal offices at
1077 Pleasant Street, Norwood, MA 02062-6714. The Company's current
manufacturing operation consists of one primary business unit engaged in
roofing manufacturing and marketing.
 
  Set forth below is certain selected consolidated financial information with
respect to the Company and its subsidiaries excerpted from the information
contained in the Company's Annual Report on Form 10-K for the fiscal year
ended December 31, 1996 (the "Company 1996 10-K") and the Company's Quarterly
Reports on Form 10-Q for the three months ended March 31, 1997, June 30, 1997
and September 30, 1997, respectively (collectively, the "Company 1997 10-Qs").
More comprehensive financial information is included in the Company 1996 10-K,
the Company 1997 10-Qs and other documents filed by the Company with the SEC,
and the following summary is qualified in its entirety by reference to the
Company 1996 10-K, the Company 1997 10-Qs and such other documents and all the
financial information (including any related notes) contained therein. The
Company 1996 10-K, the Company 1997 10-Qs and such other documents should be
available for inspection and copies thereof should be obtainable in the manner
set forth below under "Available Information."
 
                                      12

 
                               BIRD CORPORATION
 
                  SELECTED CONSOLIDATED FINANCIAL INFORMATION
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 


                                     NINE MONTHS
                                        ENDED
                                    SEPTEMBER 30,    YEAR ENDED DECEMBER 31,
                                   ---------------- --------------------------
                                    1997     1996    1996     1995      1994
                                   -------  ------- ------- --------  --------
                                                       
SUMMARY OF EARNINGS DATA:
Net sales........................  $34,438  $38,490 $51,956 $ 54,180  $167,886
Earnings (loss) from continuing
 operations......................      128    1,692   2,169     (797)    1,083
Earnings (loss) from discontinued
 operations......................       --      141     134  (11,252)   (4,766)
                                   -------  ------- ------- --------  --------
Net earnings (loss) before
 dividends.......................      128    1,833   2,303  (12,049)   (3,683)
Net earnings (loss) applicable to
 Common Shares...................   (1,024)     681     767  (13,585)   (5,219)
Net earnings (loss) per Common
 Share...........................    (0.25)    0.16    0.18    (3.31)    (1.31)
BALANCE SHEET DATA (AT END OF PE-
 RIOD):
Total assets.....................  $39,536  $44,396 $39,669 $ 43,703  $ 85,705
Working capital..................    3,102    4,480   3,375    5,978     5,627
Long-term debt, excluding current
 portion.........................        0    1,510     255    4,869    12,504
Stockholders' equity.............   24,320   25,555  25,270   24,416    37,718

 
  Available Information. The Company is subject to the informational
requirements of the Exchange Act and, in accordance therewith, is required to
file reports relating to its business, financial condition and other matters.
Information as of particular dates concerning the Company's directors and
officers, their remuneration, stock options and other matters, the principal
holders of the Company's securities and any material interest of such persons
in transactions with the Company is required to be disclosed in proxy
statements distributed to the Company's stockholders and filed with the SEC.
Such reports, proxy statements and other information should be available for
inspection at the public reference facilities of the SEC at 450 Fifth Street,
N.W., Washington, DC 20549, and at the regional offices of the SEC located at
Seven World Trade Center, 13th Floor, New York, NY 10048 and Citicorp Center,
500 West Madison Street (Suite 1400), Chicago, IL 60661. Copies of such
information should be obtainable, by mail, upon payment of the SEC's customary
charges, by writing to the SEC's principal office at 450 Fifth Street, N.W.,
Washington, DC 20549. Such material should also be available for inspection at
the offices of Nasdaq Operations, 1735 K Street, N.W., Washington, DC 20006.
The SEC maintains a web site that contains reports, proxy and information
statements and other information regarding registrants that file
electronically with the SEC. Such reports, proxy and information statements
and other information may be found on the SEC's web site address,
http://www.sec.gov.
 
  Except as otherwise stated in this Offer to Purchase, the information
concerning the Company contained herein has been taken from or based upon
publicly available documents on file with the SEC and other publicly available
information. Although the Purchaser, CertainTeed and Saint-Gobain do not have
any knowledge that any such information is untrue, none of the Purchaser,
CertainTeed or Saint-Gobain takes any responsibility for the accuracy or
completeness of such information or for any failure by the Company to disclose
events that may have occurred and may affect the significance or accuracy of
any such information.
 
9. CERTAIN INFORMATION CONCERNING THE PURCHASER, CERTAINTEED AND SAINT-GOBAIN
 
  The Purchaser, a Massachusetts corporation and a wholly owned subsidiary of
CertainTeed, was organized to acquire the Company and has not conducted any
unrelated activities since its organization. The principal office of the
Purchaser is located at the principal office of CertainTeed. All outstanding
shares of capital stock of the Purchaser are owned by CertainTeed.
 
 
                                      13

 
  The principal executive office of CertainTeed, a Delaware corporation and an
indirect wholly owned subsidiary of Saint-Gobain, is located at 750 East
Swedesford Road, Valley Forge, Pennsylvania 19482. The principal business of
CertainTeed is the manufacture of building materials (roofing, vinyl siding,
vinyl windows, ventilation products, vinyl fencing and railing, and piping
products) and fiber glass products (insulation and reinforcements).
 
  Saint-Gobain, a French corporation, is a publicly owned holding company
whose shares are listed for trading on the monthly settlement market of the
Paris Stock Exchange and on the principal European stock exchanges. Its
principal executive office is located at Les Miroirs, 18 avenue d'Alsace,
92400 Courbevoie, France (Postal Address: Les Miroirs, 92096 Paris La Defense
Cedex). The principal business of Saint-Gobain is holding interests in other
companies. Saint-Gobain has worldwide interests in businesses involving the
manufacture of flat glass, fiber glass insulation and reinforcements, pipe,
glass containers, industrial ceramics and abrasives and the manufacture and
distribution of building materials.
 
  The name, citizenship, business address, present principal occupation or
employment and five-year employment history of each of the directors and
executive officers of the Purchaser, CertainTeed, and Saint-Gobain is set
forth in Schedule I hereto and incorporated herein by reference.
 
  Because the only consideration in the Offer and Merger is cash, and in view
of the relatively small amount of consideration payable in relation to the
financial capability of Saint-Gobain and its affiliates, the Purchaser
believes the financial condition of Saint-Gobain and its affiliates is not
material to a decision by a holder of Shares whether to sell, tender or hold
Shares pursuant to the Offer. The following selected consolidated financial
information relating to Saint-Gobain and its subsidiaries, taken or derived
from the audited consolidated financial statements of Saint-Gobain for the
years ended December 31, 1994, 1995 and 1996, is provided for supplemental
information purposes only and is neither intended nor required to comply with
the requirements of the Exchange Act. The following information was prepared
in accordance with accounting principles generally accepted in France and with
International Accounting Standards ("IAS") formulated by the International
Accounting Standards Committee. These principles, as applied to Saint-Gobain
and its subsidiaries, are similar to the accounting principles generally
accepted in the United States ("US GAAP"). There are, however, a few
differences between the accounting standards applied by Saint-Gobain and its
affiliates and US GAAP with respect to certain matters, including translation,
recognition and measurement criteria.
 
  The consolidated financial statements of Saint-Gobain and its subsidiaries
are published in French francs ("FF").
 
                         SAINT-GOBAIN AND SUBSIDIARIES
 
                  SELECTED CONSOLIDATED FINANCIAL INFORMATION
                                 (IN MILLIONS)
 


                                               YEAR ENDED DECEMBER 31,
                                       ----------------------------------------
                                          1996
                                        IN U.S.
                                       DOLLARS(1)   1996      1995      1994
                                       ---------- --------- --------- ---------
                                                          
INCOME STATEMENT DATA:
Net sales............................   $14,992   FF 91,384 FF 70,310 FF 74,494
Operating income.....................     1,543       9,406     7,783     7,295
Net income...........................       709       4,323     4,212     3,625
BALANCE SHEET DATA (AT END OF PERI-
 OD):
Current assets.......................   $ 7,639   FF 46,568 FF 40,980 FF 40,503
Total assets.........................    20,664     125,960    96,492    90,755
Long-term debt (including current
 portion)............................     2,038      12,424     9,173    12,297
Net equity of consolidated entities..     9,773      59,575    46,028    42,126

- --------
(1) French francs have been translated into U.S. dollars on the basis of the
    noon buying rate (as defined below) on January 13, 1998.
 
 
                                      14

 
  In October 1997, Saint-Gobain announced its operating results for the first
six months of 1997, including sales of 52.8 billion FF ($8.7 billion),
operating income of 5.1 billion FF ($0.8 billion) and net income of 3.3
billion FF ($541 million). (French francs have been translated into U.S.
dollars on the basis of the noon buying rate on January 13, 1998.)
 
  The following table sets forth, for the periods and dates indicated, certain
information concerning the exchange rate for French francs into U.S. dollars
based upon the noon buying rate in New York City for cable transfers in
foreign currencies as determined by publicly available sources (the "noon
buying rate"):
 
                             (FF PER U.S. DOLLAR)
 


                                       AT YEAR   AVERAGE
   PERIOD                                END      RATE      HIGH       LOW
   ------                             --------- --------- --------- ---------
                                                        
   1994.............................  FF 5.3445 FF 5.5459 FF 5.9785 FF 5.1120
   1995.............................     4.8975    4.9864    5.3870    4.7755
   1996.............................     5.1928    5.1159    5.2850    4.9025
   1997.............................     6.0190    5.8386    6.3491    5.1932
   1998 (through January 13, 1998)..     6.0957    6.0872    6.1070    6.0335
   The noon buying rate on January 13, 1998 was
    $1=FF 6.0957.

 
  In fiscal year 1996, CertainTeed had net sales of approximately $1.5
billion. At September 30, 1997, CertainTeed had $1.5 billion in total assets,
$300 million in total current assets, and $804 million in total stockholder's
equity. CertainTeed's financial statements are prepared in accordance with US
GAAP.
 
10. SOURCE AND AMOUNT OF FUNDS
 
  The Purchaser estimates that the total amount of funds required to purchase
pursuant to the Offer the number of Shares that are outstanding on a fully
diluted basis and to pay fees and expenses related to the Offer will be
approximately $41 million. All funds needed for the Offer and the Merger will
be obtained from working capital of Saint-Gobain and its subsidiaries.
 
11. CONTACTS AND TRANSACTIONS WITH THE COMPANY; BACKGROUND OF THE OFFER
 
  The Offer and Merger represent the culmination of a series of negotiations
between CertainTeed and the Company that began at the Company's initiation in
1994. During the spring and early summer of that year, management of the
Company and of CertainTeed undertook to negotiate a proposed merger at a cash
price of $13 per Common Share (plus a contingent purchase price of up to $1.25
per Common Share). That transaction would also have included the redemption of
the Company's 5% Cumulative Preferred Stock, par value $100 per share (the "5%
Stock"), and the Preference Shares. In July of 1994, however, CertainTeed
informed the Company that because CertainTeed's only interest was in acquiring
the Company's roofing manufacturing business, CertainTeed was not prepared to
acquire the Company's assets and contingent liabilities unrelated to its core
roofing business. As a result, the Company and CertainTeed terminated their
negotiations. Shortly thereafter, CertainTeed indicated orally that it
remained interested in acquiring the Company's roofing plant or the entire
Company if all or a substantial portion of its non-roofing assets could be
divested prior to a CertainTeed acquisition of the Company. In September of
1994, the Company provided additional due diligence materials and suggested
continuing discussions.
 
  During the summer of 1995, the Company and CertainTeed renewed discussions,
including a meeting at CertainTeed's headquarters in Valley Forge,
Pennsylvania, at which the status of the Company's asset disposition and
contingent liability management program was discussed. The Company indicated
that all material non-roofing assets, other than its interest in a San Leon,
Texas hydrocarbon waste recycling center, had been divested and that an effort
to sell this interest was underway. During the fall of 1995, CertainTeed
resumed its due
 
                                      15

 
diligence investigation of the Company. Discussions between the parties
regarding issues raised during CertainTeed's ongoing due diligence effort
continued on a regular basis through February of 1996.
 
  In late February and early March of 1996, representatives of CertainTeed
spoke by telephone with representatives of the Company on a number of
occasions regarding the possibility of CertainTeed making a proposal to
acquire the Company. On March 4, 1996, CertainTeed indicated that (i) it was
prepared to propose an acquisition price of $7.50 per Common Share, subject to
negotiation of definitive agreements and agreement upon a satisfactory
arrangement regarding alternative transaction fees and expenses, and (ii) as
in 1994, it was prepared to cash out the Preference Shares at their
liquidation value, plus all accrued and unpaid dividends, as well as to redeem
the 5% Stock in accordance with its terms. Detailed negotiations ensued
between the Company and CertainTeed, culminating in the execution of a merger
agreement (the "1996 Merger Agreement") on March 14, 1996.
 
  On April 3, 1996, CertainTeed indicated it desired to acquire control of the
Company on the somewhat more accelerated timetable permitted by a cash tender
offer. The Board of the Company considered and approved CertainTeed's proposal
on April 5, 1996, and on April 12, 1996 a subsidiary of CertainTeed commenced
a cash tender offer (the "1996 Tender Offer") for all the outstanding Common
Shares and Preference Shares. On May 2, 1996, CertainTeed informed the Company
that CertainTeed had concluded that certain conditions to the 1996 Tender
Offer would not be satisfied at the scheduled expiration of such offer, that
CertainTeed would not waive the conditions and that, accordingly, such offer
would expire without the CertainTeed subsidiary acquiring any Shares. On May
10, 1996, the 1996 Tender Offer expired pursuant to its terms without the
CertainTeed subsidiary acquiring any Shares; thereafter, the 1996 Merger
Agreement was terminated.
 
  On December 11 and 12, 1997, Bradford C. Mattson, Executive Vice President,
Exterior Products Group, of CertainTeed, spoke by telephone with Richard C.
Maloof, the Company's President, regarding the possibility of a renewed
interest by CertainTeed of making a proposal to acquire the Company. During
these conversations, Mr. Mattson was informed that two other prospective
purchasers were conducting investigations of the Company and would likely
submit acquisition proposals to the Company. On December 14, 1997, Mr. Mattson
had another telephone conversation with Mr. Maloof to discuss, among other
things, several environmental matters relating to the Company. On December 15,
1997, John R. Mesher, Vice President and General Counsel of CertainTeed, spoke
by telephone with Frank S. Anthony, the Company's General Counsel, to discuss
the timetable and process for CertainTeed to explore acquiring the Company.
Mr. Mesher was advised that in order for CertainTeed to be involved in the
process, a meaningful, but non-binding, proposal would have to be submitted on
or prior to December 18, 1997. On the evening of December 15, 1997,
representatives of CertainTeed (Mr. Mattson, Mickey Trapnell, Vice President-
Finance Controller, Roofing Products Group, and Rudy T. Lee, Vice President-
Sales, Roofing Products Group) had a dinner meeting with Messrs. Maloof and
Anthony. This dinner meeting was followed the next day by a tour of the
Company's facilities and properties and a review of the Company's operations
by Messrs. Mattson, Trapnell and Lee, as well as James E. Hilyard, the
President of CertainTeed's Roofing Products Group. In addition, over the next
several days, James J. Smith, CertainTeed's Director of Environmental Affairs,
discussed with Mr. Maloof several environmental issues relating to the Company
and its operations.
 
  On December 18, 1997, CertainTeed submitted to the Company a non-binding
expression of interest confirming CertainTeed's interest in acquiring all of
the equity of the Company for an aggregate purchase price of about $39.5
million. Between December 20, 1997 and December 22, 1997, Messrs. Maloof
and/or Anthony spoke by telephone with Mr. Mesher and/or George B. Amoss,
CertainTeed's Vice President-Finance, to discuss questions that the Company's
management and Board of Directors had with respect to CertainTeed's expression
of interest. Detailed negotiations then ensued between the Company and
CertainTeed, culminating in agreement on the terms of the Merger Agreement. At
a meeting on January 12, 1998, the Board of Directors of the Company
unanimously determined that the Merger is fair to, and in the best interests
of, the Company and the Company's stockholders and approved the Merger
Agreement and recommended that the holders of Shares tender their Shares
pursuant to the Offer and vote in favor of approval and adoption of the Merger
Agreement. The Merger Agreement was executed and delivered by the parties on
January 12, 1998. On that same date, the Directors of
 
                                      16

 
the Company also executed a Stockholder Agreement which commits them to tender
their Shares to CertainTeed in connection with the Offer and to vote in favor
of the Merger. The Company and CertainTeed issued a joint press release
regarding the Offer and Merger Agreement on January 13, 1998.
 
  Except as described in this Offer to Purchase, none of the Purchaser,
CertainTeed, Saint-Gobain or, to the best knowledge of the Purchaser,
CertainTeed and Saint-Gobain, any of the persons listed in Schedule I, or any
associate or majority-owned subsidiary of the Purchaser, CertainTeed, Saint-
Gobain or any of the persons so listed, beneficially owns or has the right to
acquire any equity security of the Company, and none of the Purchaser,
CertainTeed, Saint-Gobain or, to the best knowledge of the Purchaser,
CertainTeed and Saint-Gobain, any of the other persons referred to above, or
any of the respective directors, executive officers or subsidiaries of any of
the foregoing, has effected any transaction in any equity security of the
Company during the past 60 days. The Purchaser, CertainTeed and Saint-Gobain
disclaim beneficial ownership of any Shares owned by any pension plan of
Saint-Gobain or any affiliate of Saint-Gobain.
 
  The Chairman, President and Chief Executive Officer of Mellon Bank
Corporation and Mellon Bank, N.A. is also a director of Saint-Gobain
Corporation, an indirect wholly owned subsidiary of Saint-Gobain and the U.S.
holding company of CertainTeed. Based on information contained in a Schedule
13G amended through February 10, 1997 filed with the SEC, Mellon Bank
Corporation, an affiliate of Mellon Bank, N.A., had beneficial ownership of
309,000 Common Shares representing 7.5% of the outstanding Common Shares,
including sole voting power and sole dispositive power with respect to 20,000
Common Shares and Mellon Bank Corporation together with its subsidiaries,
including Boston Safe Deposit and Trust Company and Mellon Bank, N.A., had
shared voting and dispositive power with respect to 289,000 Common Shares,
including 274,929 Common Shares held in a trust with Charles S. Bird, III as
co-trustee with shared voting and dispositive power.
 
  Except as otherwise set forth in this Offer to Purchase, (1) there have not
been any contacts, transactions or negotiations between the Purchaser,
CertainTeed, Saint-Gobain, any of their respective subsidiaries or, to the
best knowledge of the Purchaser, CertainTeed and Saint-Gobain, any of the
persons listed in Schedule I, on the one hand, and the Company or any of its
directors, executive officers or affiliates, on the other hand, that are
required to be disclosed pursuant to the rules and regulations of the SEC, (2)
there are no present or proposed material contracts, arrangements,
understandings or relationships between the Purchaser, CertainTeed, Saint-
Gobain, their respective controlling persons or subsidiaries or, to the best
knowledge of the Purchaser, CertainTeed and Saint-Gobain, any of the persons
listed in Schedule I, on the one hand, and the Company or any of its
controlling persons, subsidiaries, executive officers or directors, on the
other hand, and (3) none of the Purchaser, CertainTeed, Saint-Gobain or, to
the best knowledge of the Purchaser, CertainTeed and Saint-Gobain, any of the
persons listed in Schedule I has any contract, arrangement, understanding or
relationship with any person with respect to any securities of the Company.
CertainTeed has had preliminary discussions with Richard C. Maloof, the
President of the Company, and Frank S. Anthony, Vice President, General
Counsel and Corporate Secretary of the Company, regarding their continued
employment with the Surviving Corporation on terms which have yet to be
decided, but these discussions have not yet resulted in any commitments by any
of the parties.
 
12. PURPOSE OF THE OFFER; THE MERGER AGREEMENT; THE STOCKHOLDER AGREEMENT;
PLANS FOR THE COMPANY
 
  Purpose. The purpose of the Offer and the Merger is to enable CertainTeed,
through the Purchaser, to acquire control of, and the entire equity interest
in, the Company. The Offer, as the first step in the acquisition of the
Company, is intended to facilitate the acquisition of all the Shares. The
Purchaser currently intends, as soon as practicable following consummation of
the Offer, to hold a special meeting of stockholders to approve the Merger
(the "Special Meeting") and, as soon as practicable thereafter, to consummate
the Merger.
 
  The Merger Agreement. The Merger Agreement provides that following the
satisfaction or waiver of the conditions described below under "Conditions to
the Merger", the Purchaser will be merged with and into the Company, and each
then outstanding Share (other than Shares held by stockholders who perfect
their appraisal rights under Massachusetts law, Shares held in the Company's
treasury and Shares held directly by the Purchaser
 
                                      17

 
or CertainTeed) will be converted into the right to receive an amount in cash
equal to (in the case of Common Shares) $5.50 per Common Share and (in the
case of Preference Shares) $20, which amount shall not be adjusted for any
accrued and unpaid dividends as of the Effective Date, per Preference Share.
All outstanding shares of the Company's 5% Stock will remain issued and
outstanding after the Merger and will be called for redemption and retirement
as soon as practicable following the Merger at a price equal to $110 per
share, plus all accrued and unpaid dividends thereon as of the date of
redemption and retirement.
 
  (1) Vote Required to Approve Merger. If the Purchaser acquires, through the
Offer or otherwise (i) at least 66 2/3% of the outstanding Common Shares and
(ii) at least 66 2/3% of the outstanding Preference Shares, which would be the
case if the Minimum Condition were satisfied, it would have sufficient voting
power to effect the Merger without the vote of any other stockholder of the
Company.
 
  (2) Conditions to the Merger.
 
  (A) Conditions to the Obligations of CertainTeed and the Purchaser. The
obligations of CertainTeed and the Purchaser under the Merger Agreement are
subject to the satisfaction, on or prior to the closing date of the Merger
(the "Closing Date"), of each of the following conditions, each of which may
be waived by CertainTeed and the Purchaser except as otherwise provided by
law, provided that upon the acceptance of any Common Shares and Preference
Shares, if any, by the Purchaser pursuant to the Offer (the "Consummation of
the Offer") each of the following conditions (other than the conditions set
forth in clauses (iii)(b), (iii)(d) and (iv)(b) below) shall be deemed waived
by the Purchaser and CertainTeed: (i) the representations and warranties of
the Company contained in the Merger Agreement (without regard to any
supplemental information provided after the date of the Merger Agreement) that
are qualified as to materiality shall be true and correct, and the
representations that are not so qualified shall be true and correct in all
material respects, in each case on and as of the date of the Merger Agreement
and on and as of the effective date of the Merger (the "Effective Date"), and
between the date of the Merger Agreement and the Effective Date there shall
not have been any event or change in circumstance causing or reasonably
anticipated to cause in the future (a) any material adverse effect on the
business, assets, properties, condition (financial or other) or results of
operations of the Company and its subsidiaries taken as a whole or the
Surviving Corporation and its subsidiaries taken as a whole or (b) any
material adverse effect on the ability of the Company to carry out the
transactions contemplated by the Merger Agreement without significant
unanticipated delay or expense (clauses (a) and (b) together being a "Material
Adverse Effect"); (ii) each of the obligations of the Company to be performed
by it on or before the Closing Date pursuant to the terms of the Merger
Agreement shall have been duly performed or complied with in all material
respects by the Closing Date; (iii)(a) all corporate action necessary by the
Company to authorize the execution, delivery and performance of the Merger
Agreement and the consummation of the transactions contemplated thereby
(including the Offer and the Merger) shall have been duly and validly taken,
and the Company and the Purchaser shall have full right and power to merge on
the terms provided in the Merger Agreement; (b) the holders of the Common
Shares and the Preference Shares shall have duly approved the Merger at the
Special Meeting (other than if such approval shall not have occurred solely
due to the breach by CertainTeed or the Purchaser of its obligation, upon
consummation of the Offer, to vote its Common Shares and Preference Shares in
favor of the Merger); (c) all consents, approvals and authorizations from
third persons and governmental authorities identified in the Schedules to the
Merger Agreement required to consummate the transactions contemplated by the
Merger Agreement shall have been obtained; and (d) all applicable waiting
periods under the HSR Act shall have expired or been terminated; (iv)(a) there
shall not be any pending or threatened suit, action or proceeding by any
governmental authority (1) challenging the acquisition by CertainTeed or the
Purchaser of any Shares, seeking to restrain or prohibit the consummation of
the Merger or any of the other transactions contemplated by the Merger
Agreement that are material in relation to the Company and its subsidiaries
taken as a whole, (2) seeking to prohibit or limit the ownership or operation
by the Company, CertainTeed or any of their respective subsidiaries of any
material portion of the business or assets of the Company, or any of their
respective subsidiaries, or to compel the Company, CertainTeed or any of their
respective subsidiaries to dispose of or hold separate any material portion of
the business or assets of the Company, CertainTeed or any of their respective
subsidiaries, as a result of the Merger or any of the other transactions
contemplated by the Merger Agreement, (3) seeking to impose limitations on the
ability of
 
                                      18

 
CertainTeed or the Purchaser to acquire or hold, or exercise full rights of
ownership of, any shares of common stock of the Surviving Corporation, (4)
seeking to prohibit CertainTeed or any of its subsidiaries from effectively
controlling in any material respect the business or operations of the Company
or its subsidiaries or of CertainTeed and its subsidiaries or (5) which
otherwise is reasonably likely to have a Material Adverse Effect, (b) no
statute, rule, regulation, executive order, decree, temporary restraining
order, preliminary or permanent injunction or other order or legal restraint
or prohibition enacted, entered, promulgated, enforced, issued or deemed
applicable to the Merger or the transactions contemplated thereby, or any
other action shall be taken by any governmental authority or court, in each
case preventing the consummation of the Merger or the transactions
contemplated thereby, shall be in effect; (v) all directors of the Company
whose resignation is requested by CertainTeed at least five days before the
Closing Date will have submitted their resignations effective as of the
Closing Date; (vi) no more than ten percent of the issued and outstanding
shares of any class of equity securities of the Company entitled to dissenters
rights as of the Closing Date shall be dissenting shares entitled to receive
the fair value of such shares in accordance with Sections 85 through 98
inclusive of the Massachusetts Business Corporation Law (the "MBCL");
(vii) each outstanding option (each a "Stock Option") issued under the
Company's 1982 Stock Option Plan, as amended (the "1982 Stock Option Plan"),
the Company's 1992 Stock Option Plan, as amended (the "1992 Stock Option
Plan") and the Company's 1992 Non-Employee Directors Stock Option Plan, as
amended (the "Director Option Plan") shall have been amended to effect the
transactions contemplated by the Merger Agreement; and (viii) the Company
shall have furnished CertainTeed with such certificates of its officers and
others to evidence compliance with the conditions set forth in the Merger
Agreement as may be reasonably requested by CertainTeed, and the form and
substance of all opinions, certificates and other documents required by or
furnished pursuant to the Merger Agreement shall be satisfactory in all
reasonable respects to CertainTeed and its counsel.
 
  (B) Conditions to the Obligations of the Company. The obligations of the
Company under the Merger Agreement are subject to the satisfaction, on or
prior to the Closing Date, of each of the following conditions, each of which
may be waived by the Company except as otherwise provided by law, provided
that, upon Consummation of the Offer, each of the following conditions (other
than the conditions set forth in clauses (iii) and (iv) below) shall be deemed
waived by the Company: (i) the representations and warranties of CertainTeed
and the Purchaser contained in the Merger Agreement that are qualified as to
materiality shall be true and correct, and the representations that are not so
qualified shall be true and correct in all material respects, in each case on
and as of the date of the Merger Agreement and on and as of the Effective
Date; (ii) each of the obligations of CertainTeed and the Purchaser to be
performed by them on or before the Closing Date pursuant to the terms of the
Merger Agreement shall have been duly performed and complied with in all
material respects by the Closing Date ; (iii)(a) all corporate action
necessary by the Purchaser and CertainTeed to authorize the execution,
delivery and performance of the Merger Agreement and the consummation of the
transactions contemplated by the Merger Agreement shall have been duly and
validly taken, the Purchaser shall have full right and power to merge on the
terms provided in the Merger Agreement and the Company's stockholders shall
have approved the Merger at the Special Meeting called for that purpose; (b)
all consents, approvals and authorizations from third persons and governmental
authorities identified in the Schedules to the Merger Agreement required to
consummate the transactions contemplated by the Merger Agreement shall have
been obtained; and (c) all applicable waiting periods under the HSR Act shall
have expired or been terminated; (iv) no judicial, administrative or
arbitration order, award, judgment, writ, injunction or decree shall have been
entered by a governmental authority with proper jurisdiction and not revised
prohibiting the Merger, and no legal action shall have been instituted by any
governmental authority challenging the Merger which if successful would
prohibit the consummation of the Merger; and (v) CertainTeed and the Purchaser
shall have furnished the Company with such certificates of their respective
officers and others to evidence compliance with the conditions set forth in
the Merger Agreement as may be reasonably requested by the Company, and the
form and substance of all certificates and other documents required by or
furnished pursuant to the Merger Agreement shall be satisfactory in all
reasonable respects to the Company and its counsel.
 
  (3) Termination of the Merger Agreement. Unless the Consummation of the
Offer shall have occurred and Designated Directors (as defined below) shall
constitute at least a majority of the members of the Board of the Company, the
Merger Agreement shall be terminated, and the Merger abandoned, if the
requisite vote of the
 
                                      19

 
Company's stockholders with respect to the Merger Agreement is not obtained as
contemplated by the Merger Agreement. Notwithstanding approval of the Merger
Agreement and the transactions contemplated thereby by the stockholders of the
Company or by CertainTeed, the Merger Agreement may be terminated, and the
Offer and Merger abandoned, at any time prior to the Effective Date:
 
    (A) by mutual consent of CertainTeed, the Purchaser and the Company;
 
    (B) unless the Consummation of the Offer shall have occurred and
  Designated Directors shall constitute at least a majority of the members of
  the Board of the Company, by CertainTeed, the Purchaser or the Company at
  any time after June 30, 1998;
 
    (C) by CertainTeed or the Purchaser if (a) the Offer terminates without
  any Shares being accepted for payment due to (x) failure of the Minimum
  Condition or (y) any of the other conditions to the Offer (other than
  solely the condition described in paragraph (c) of Section 14 "Certain
  Conditions of the Offer") shall have become impossible to fulfill and shall
  not have been waived (see Section 14), (b) any of the conditions to the
  obligations of CertainTeed and the Purchaser to consummate the Merger
  becomes impossible to fulfill and shall not have been waived or deemed
  waived in accordance with the Merger Agreement (it being understood that
  with respect to any condition described in clause (iv) (b) of paragraph
  (2)(A) under The Merger Agreement above in this Section 12, any condition
  described therein relating to an order, injunction or judicial decree shall
  be deemed not to have become impossible to fulfill until such order,
  injunction or decree shall have become final and non-appealable), (c) the
  Board of the Company withdraws or modifies its approval or recommendation
  of the Merger Agreement, the Offer or the Merger or (d) unless the
  Consummation of the Offer shall have occurred and Designated Directors
  shall constitute at least a majority of the members of the Board of the
  Company, the Company fails to perform in any material respect any of its
  obligations under the Merger Agreement or breaches in any material respect
  any provision of the Merger Agreement, and the Company has failed to
  perform such obligation or cure such breach within 10 days of its receipt
  of written notice thereof from CertainTeed or the Purchaser, and such
  failure to perform shall not have been waived in accordance with the terms
  of the Merger Agreement; or
 
    (D) by the Company if (a) any of the conditions to the obligations of the
  Company to consummate the Merger shall become impossible to fulfill and
  shall not have been waived in accordance with the terms of the Merger
  Agreement, (b) CertainTeed or the Purchaser fails to perform in any
  material respect any of its obligations under the Merger Agreement or
  breaches in any material respect any provision of the Merger Agreement, and
  CertainTeed and the Purchaser have failed to perform such obligation or
  cure such breach within 10 days of receipt of written notice thereof from
  the Company, and such failure to perform shall not have been waived in
  accordance with the terms of the Merger Agreement, (c)(i) the Board of the
  Company withdraws or modifies its approval or recommendation of the Merger
  Agreement, the Offer or the Merger and (ii) the Company pays CertainTeed in
  cash all CertainTeed's Expenses and the Alternate Transaction Fee (each as
  defined in the first paragraph under "Fees and Expenses" below) or (d) if
  the Purchaser (i) shall have failed to commence the Offer within the time
  required under the Exchange Act or (ii) shall have failed to pay for any
  Shares accepted for payment pursuant to the Offer and, in the case of
  clause (ii), the Purchaser shall have failed to make such payment within
  three business days of receipt of written notice thereof from the Company.
 
  Notwithstanding any provisions to the contrary in the Merger Agreement, (i)
the sole remedy of CertainTeed or the Purchaser for a breach by the Company of
any representation or warranty set forth in the Merger Agreement shall be the
termination of the Merger Agreement (if permitted by the Merger Agreement)
unless such breach was made with the actual knowledge of the President of the
Company or the Vice President and General Counsel of the Company, after due
inquiry of other managerial employees of the Company who would be reasonably
expected to have knowledge as to the matter represented (a "Company Willful
Misrepresentation") and (ii) the sole remedy of the Company for a breach by
CertainTeed or the Purchaser of any representation or warranty set forth in
the Merger Agreement shall be the termination of the Merger Agreement (if
permitted by the Merger Agreement) unless such breach was made with the actual
knowledge of the President or Executive Vice President of CertainTeed, after
due inquiry of other managerial employees of
 
                                      20

 
CertainTeed who would be reasonably expected to have knowledge as to the
matter represented (a "CertainTeed Willful Misrepresentation").
 
  (4) Procedure for Termination and Amendment. The Merger Agreement provides
that the termination or amendment of the Merger Agreement pursuant to the
Merger Agreement requires in the case of the Company action by its Board or
the duly authorized designee of its Board in order to be effective. In the
event that the Purchaser's designees are appointed or elected to the Board of
the Company as provided in the Merger Agreement, after the Consummation of the
Offer and prior to the time the Merger becomes effective, the affirmative vote
of at least a majority of the Continuing Directors shall be required for the
Company to agree to amend, waive compliance with or terminate the Merger
Agreement.
 
  (5) Takeover Proposals. The Merger Agreement provides that the Company shall
not, nor shall it permit any of its subsidiaries or affiliates to, nor shall
it authorize or permit any officer, director or employee of, or any investment
banker, attorney or other advisor or representative of the Company or any of
its subsidiaries to (a) solicit or initiate, or knowingly encourage the
submission of, any takeover proposal, (b) participate in any discussions or
negotiations regarding, or furnish to any person any information with respect
to, any takeover proposal (except for (i) non-confidential information, or
(ii) filings with the SEC); provided, however, that prior to the earlier of
the Consummation of the Offer or the Special Meeting, to the extent required
by the fiduciary obligations of the Board of the Company, as determined in
good faith by the Board of the Company based on the advice of counsel, the
Company may, (A) in response to an unsolicited request therefor, furnish
information with respect to the Company (pursuant to a confidentiality
agreement at least as restrictive (as determined by the Company's counsel) as
the Confidentiality Agreement dated April 13, 1994, as amended, between the
Company and Saint-Gobain Corporation, a Pennsylvania corporation and an
indirect wholly owned subsidiary of Saint-Gobain) to any person who has
indicated to the Company that it is interested in pursuing a qualified
takeover proposal and discuss such information (but not the terms of any
possible takeover proposal) with such person and (B) upon receipt by the
Company of a qualified takeover proposal, following the delivery to
CertainTeed of the notice required pursuant to the Merger Agreement,
participate in discussions or negotiations regarding such qualified takeover
proposal. Without limiting the foregoing, it is understood that any violation
of the restrictions described in the preceding sentence by any officer of the
Company or any of its subsidiaries or any investment banker, attorney or other
advisor or representative of the Company or its subsidiaries shall be deemed a
breach of the Merger Agreement by the Company. For purposes of this Section
under the heading "Takeover Proposals", "takeover proposal" means any proposal
for a merger or other business combination (regardless of legal form)
involving the Company or any subsidiary or any proposal or offer to acquire in
any manner, directly or indirectly, a substantial portion of the assets or
business of the Company or a substantial equity interest in, or any
substantial amount of voting securities of, the Company or any subsidiary, or
any other transaction outside the ordinary course of business and not
otherwise specifically permitted by the terms of the Merger Agreement the
consummation of which would impede or prevent the consummation of the Merger
pursuant to the terms of the Merger Agreement; and "qualified takeover
proposal" means a takeover proposal having terms which the Board of the
Company determines (based on, among other things, the advice of a financial
advisor of nationally recognized reputation) and after giving due
consideration to the Stockholder Agreement in its good faith reasonable
judgment to be more favorable to the holders of Common Shares than the Common
Price and to the holders of Preference Shares than the Preference Price and
likely to be fully financed and consummated.
 
  The Merger Agreement provides further that, except as described below,
neither the Company's Board nor any committee thereof shall (i) withdraw or
modify or propose to withdraw or modify, in a manner adverse to CertainTeed or
the Purchaser, the approval or recommendation by such Board or any such
committee of the Merger Agreement, the Offer or the Merger, (ii) approve or
recommend, or propose to approve or recommend, any takeover proposal or (iii)
enter into any agreement with respect to any takeover proposal.
Notwithstanding the foregoing, in the event the Board of the Company receives
a qualified takeover proposal, the Board of the Company or any committee
thereof or the Company may (subject to the limitations in the preceding
paragraph) withdraw or modify its approval or recommendation of the Merger
Agreement, the Offer or the Merger at any time after 48 hours following
CertainTeed's receipt of written notice (a "Notice of Qualified Takeover
Proposal") advising CertainTeed that the Board of the Company has received a
qualified takeover proposal, specifying the material terms and conditions of
such qualified takeover proposal and identifying the person
 
                                      21

 
making such qualified takeover proposal. The Company may take any of the
foregoing actions pursuant to the provision described in the preceding
sentence only until the earlier of the Consummation of the Offer or the
approval of the Merger at the Special Meeting. The Company shall not be
prohibited from taking and disclosing to its stockholders a position
contemplated by SEC Rule 14e-2(a) under the Exchange Act following
CertainTeed's receipt of a Notice of Qualified Takeover Proposal provided that
the Company does not withdraw or modify its position with respect to the
Merger or approve or recommend a takeover proposal.
 
  In addition to the obligations of the Company described in the preceding
paragraphs, the Company shall promptly advise CertainTeed orally and in
writing of any request for information or of any takeover proposal, or any
inquiry with respect to any takeover proposal, the material terms and
conditions of such request, takeover proposal or inquiry and the identity of
the person making any such takeover proposal or inquiry. The Company shall
keep CertainTeed fully informed of the status and details of any such request,
takeover proposal or inquiry.
 
  (6) Fees and Expenses. Except with respect to the circumstances described
below, the Merger Agreement provides that each of the Purchaser, CertainTeed
and the Company will bear its own costs, fees and expenses in connection with
the negotiation, execution, delivery and performance of the Merger Agreement
and the consummation of the Offer and the Merger.
 
  The Merger Agreement provides that in the event that the Board of the
Company wishes to withdraw or adversely modify its approval or recommendation
of the Merger Agreement, the Offer or the Merger, prior to such withdrawal or
modification the Company shall pay in same day funds to CertainTeed (a) its
Expenses (defined below) incurred to date and thereafter shall pay in same day
funds to CertainTeed within one business day after demand therefor all
subsequently incurred Expenses, provided, that the Company shall not be
obligated to pay any such Expenses to the extent they exceed an aggregate of
$1 million, and (b) an alternate transaction fee of $1.5 million (the
"Alternate Transaction Fee"). In the event the Company receives a takeover
proposal from a person other than CertainTeed or one of its affiliates or a
takeover proposal is publicly disclosed prior to the Expiration Date (or in
the case of clauses (ii) and (iii), prior to the Special Meeting) or, if
earlier, termination of the Merger Agreement, and (i) at the Expiration Date a
sufficient number of Shares shall not have been tendered to satisfy the
Minimum Condition, (ii) at the Special Meeting the required approval of the
Merger by the Company's stockholders is not obtained, or (iii) the Merger
Agreement is terminated (other than by the Company if the Board of the Company
withdraws or modifies its approval or recommendation of the Merger Agreement
or the Merger) prior to a vote on the Merger at the Special Meeting unless the
Consummation of the Offer shall have occurred, the Company shall pay in same
day funds to CertainTeed within two business days after the earlier of such
Expiration Date, Special Meeting or termination of the Merger Agreement (a)
all Expenses incurred to date, and thereafter will pay in same day funds to
CertainTeed within one business day after demand therefor, all subsequently
incurred Expenses, provided, that the Company shall not be obligated to pay
any such Expenses to the extent they exceed an aggregate of $1 million, and
(b) the Alternate Transaction Fee. With regard to the immediately preceding
sentence, "Expenses" means all out-of-pocket fees and expenses (including
without limitation all travel expenses and all fees and expenses of counsel,
investment banking firms, accountants, experts and consultants to CertainTeed
or the Purchaser) incurred or paid by or on behalf of CertainTeed or the
Purchaser after January 1, 1996 in connection with or leading to the Merger
Agreement, the transactions contemplated thereby, and performing or securing
the performance of the obligations of the parties thereunder, including,
without limitation, such fees and expenses related to preparation and
negotiation of documentation and conducting due diligence. CertainTeed is
required within 36 hours after request therefor to advise the Company of an
estimate of its Expenses if the Company wishes to withdraw or modify its
approval or recommendation of the Merger Agreement, the Offer or the Merger
pursuant to the Merger Agreement.
 
  The Merger Agreement also provides that in the event that the Merger
Agreement is terminated, the Offer is terminated or the Merger does not occur
(i) solely due to a breach by CertainTeed or the Purchaser of any of its
covenants or obligations under the Merger Agreement or due to a CertainTeed
Willful Misrepresentation or (ii) solely due to a breach by the Company of any
of its covenants or obligations under the Merger Agreement
 
                                      22

 
or due to a Company Willful Misrepresentation, then in the case of a
termination pursuant to clause (i) above, CertainTeed and the Purchaser shall
promptly pay to the Company, and in the case of termination pursuant to clause
(ii) above, the Company shall promptly pay to CertainTeed and the Purchaser,
in same day funds all Expenses (as defined below) incurred to date (after
giving credit for any reimbursement of expenses already made pursuant to the
provisions described in the immediately preceding paragraph) and thereafter
shall pay in same day funds within one business day after demand therefor all
subsequently incurred Expenses. With regard to the preceding sentence,
"Expenses" means all out-of-pocket fees and expenses (including without
limitation all travel expenses and all fees and expenses of counsel,
investment banking firms, accountants, experts and consultants to CertainTeed
or the Company, as the case may be) incurred or paid by or on behalf of
CertainTeed, the Purchaser or the Company, as the case may be, after January
1, 1996 in connection with or leading to the Merger Agreement, the
transactions contemplated thereby, and performing or securing performance of
the obligations of the parties thereunder, including, without limitation, such
fees and expenses related to preparation and negotiation of documentation and
conducting due diligence. Nothing described in this or the immediately
preceding paragraph limits damages that would otherwise be recoverable for
breaches under the Merger Agreement.
 
  (7) Conduct of Business by the Company. Pursuant to the Merger Agreement,
except as otherwise expressly contemplated or permitted by the Merger
Agreement or otherwise consented to or approved by an authorized officer of
CertainTeed, the Company has agreed that prior to the Effective Date (or, if
earlier, when a majority of the members of the Board of the Company are
designees of the Purchaser in accordance with the Merger Agreement) the
business of the Company and its subsidiaries shall be conducted in the
ordinary course consistent with past practice and: (a) no change will be made
in the respective articles or certificate of organization or incorporation or
by-laws of the Company or any of its subsidiaries; (b) no change shall be made
in the number of shares of the Company's authorized, issued or outstanding
capital stock; nor shall any conversion rights by which the Company or any
subsidiary is or may become bound to issue, transfer, sell, repurchase or
otherwise acquire or retire any shares of capital stock or other ownership
interest of the Company or any subsidiary, or any securities convertible into
or exchangeable or exercisable for any such shares or other ownership interest
be granted, made, redeemed or amended; nor will the Company or any subsidiary
issue, deliver, pledge or sell any such shares, securities or obligations
(except deliveries or pledges in favor of the Company's senior lenders);
provided, however, that the Company is permitted to issue shares or other
securities as contemplated by the Company's Employee's Savings and Profit
Sharing Plan (the "Savings Plan") as in effect on the date of the Merger
Agreement and is permitted to issue Common Shares in connection with the due
exercise of Stock Options issued pursuant to the 1982 Stock Option Plan, the
1992 Stock Option Plan, the Director Option Plan or any other right or
convertible security outstanding as of the date of the Merger Agreement in
accordance with the existing terms thereof; (c) no dividend shall be declared
or paid or other distribution (whether in cash, stock, property or any
combination thereof) or payment declared or made in respect of the Common
Shares, 5% Stock or Preference Shares or any other outstanding capital stock
of the Company, nor shall the Company or any subsidiary (i) purchase, acquire
or redeem any Common Shares, 5% Stock or Preference Shares or (ii) split,
combine or reclassify any of its capital stock or issue or authorize the
issuance of any other securities in respect of, in lieu of or in substitution
for shares of its capital stock; (d) neither the Company nor any subsidiary
shall enter into any material contract, or except in the ordinary course of
business consistent with past practice any other agreement, commitment or
instrument; (e) the Company shall use and shall cause each subsidiary to use
its and their respective reasonable efforts to preserve its and their business
organization intact, to keep available the services of its and their officers
and present key employees and to preserve its and their properties and the
goodwill of its and their suppliers, customers and others with whom business
relationships exist; (f) the Company shall not take, agree to take or permit
any subsidiary to take any action or do or permit to be done anything in the
conduct of its business or that of any subsidiary which would be contrary to
or in breach of any of the terms or provisions of the Merger Agreement or
which would cause any of the representations of the Company contained in the
Merger Agreement to be or become untrue in any material respect; (g) neither
the Company nor any of its subsidiaries shall adopt or amend in any material
respect or terminate any benefit plan, except as required by law, or change
any actuarial or other assumption used to calculate funding obligations with
respect to any Company pension plan (except to the extent that failure to make
such change would result in
 
                                      23

 
noncompliance with generally accepted accounting principles ("GAAP"), the
Employee Retirement Income Security Act of 1974, as amended ("ERISA"), or the
Code, or change the manner in which contributions to any Company pension plan
are made or the basis on which such contributions are determined, except as
required by applicable law; (h) the Company shall not acquire or agree to
acquire (x) by merging or consolidating with, or by purchasing a substantial
portion of the assets of, or by any other manner, any business or any
corporation, partnership, joint venture, association or other business
organization or division thereof or (y) any assets that are material,
individually or in the aggregate, to the Company and its subsidiaries taken as
a whole, except purchases of inventory, raw materials, supplies and similar
materials in the ordinary course of business consistent with past practice and
capital expenditures complying with clause (k) below; (i) the Company shall
not sell, lease, license, mortgage or otherwise encumber or subject to any
lien (except in favor of the Company's senior lenders or certain liens
permitted under the Merger Agreement) or otherwise dispose of any of its
material properties or assets, except bona fide sales of inventory in the
ordinary course of business consistent with past practice; (j) the Company
shall not (i) incur any indebtedness for borrowed money or guarantee any such
indebtedness of another person, issue or sell any debt securities or warrants
or other rights to acquire any debt securities of the Company or any of its
subsidiaries, guarantee any debt securities of another person, enter into any
"keep well" or other agreement to maintain any financial statement condition
of another person or enter into any arrangement having the economic effect of
any of the foregoing, except for short-term borrowings incurred in the
ordinary course of business consistent with past practice and routine
endorsements in the process of collection, or (ii) make any loans, advances or
capital contributions to, or investments in, any other person, other than to
the Company or any direct or indirect wholly owned subsidiary of the Company
or routine travel and similar advances to employees; (k) the Company shall not
make or agree to make any new capital expenditure or expenditures which,
individually, is in excess of $100,000 or, in the aggregate, are in excess of
$250,000; (l) the Company shall not make any tax election or settle or
compromise any income tax liability; provided that CertainTeed shall not
unreasonably withhold any consent or approval of any such tax election,
settlement or compromise; (m) the Company shall not pay, discharge or satisfy
any material claims, liabilities or obligations (absolute, accrued, asserted
or unasserted, contingent or otherwise), other than the payment, discharge or
satisfaction, in the ordinary course of business consistent with past practice
or in accordance with their terms, of liabilities that are reflected or
reserved against in the Company's balance sheet as of September 30, 1997, or
incurred since the date of such balance sheet in the ordinary course of
business consistent with past practice, or waive the benefits of, or agree to
modify in any manner, any confidentiality, standstill or similar agreement to
which the Company or any of its subsidiaries is a party, except as permitted
by the Merger Agreement; and (n) the Company shall not authorize any of, or
commit or agree to take any of, the foregoing actions.
 
  In addition, without the prior consent of an authorized officer of
CertainTeed, which consent shall not be unreasonably withheld, the Company
shall not make any election fixing the rate or rates payable under the
Company's revolving credit agreement for a term that could reasonably be
expected to extend beyond the Effective Date.
 
  The Merger Agreement requires CertainTeed to respond within a reasonable
period of time to any request for consent or approval required to take any of
the actions described in the preceding paragraphs.
 
  The Merger Agreement also requires that the Company promptly advise
CertainTeed orally and in writing of any change or event of which the Company
has knowledge having, or which, insofar as can reasonably be foreseen, would
have, a Material Adverse Effect.
 
  (8) Directors. Subject to compliance with applicable law (including Section
14(f) of the Exchange Act), upon the acquisition by the Purchaser of at least
a majority of the outstanding Common Shares pursuant to the Offer, the
Purchaser shall be entitled to designate at least a majority of the members of
the Board of Directors of the Company, and the Company and its Board of
Directors shall, at such time, take any and all such action (including to
increase the size of the Board of Directors or to use their best efforts to
cause directors to resign) needed to cause a sufficient number of the
Purchaser's designees to be appointed to the Company's Board of Directors such
that the designees shall constitute such majority (any director so designated
by the Purchaser, a
 
                                      24

 
"Designated Director"). It is understood that immediately after the
acquisition by the Purchaser of at least a majority of the outstanding Common
Shares pursuant to the Offer (x) the Company's Board of Directors shall
consist of seven members, (y) the initial designees of the Purchaser to the
Company's Board of Directors are expected to be George B. Amoss, Gianpaolo
Caccini, James E. Hilyard and Bradford C. Mattson and (z) the remaining
members of the Company's Board of Directors are expected to be Frank Anthony,
Antonio J. Lorusso, Jr. and Richard C. Maloof. In the event that, after the
acquisition by the Purchaser of at least a majority of the outstanding Common
Shares pursuant to the Offer and prior to the Effective Time (as defined in
the Merger Agreement), the number of members of the Board of Directors
increases (including pursuant to the provisions of the Preference Shares and
the 5% Stock), the Company and its Board of Directors shall, at such time,
take any and all such additional action (including to increase the size of the
Board of Directors, to use their best efforts to cause additional directors to
resign and to appoint additional designees of the Purchaser) needed to cause a
sufficient number of the Purchaser's designees to be appointed to the Board of
Directors such that the designees shall then constitute at least a majority of
the members of the Board of Directors. The Company, CertainTeed and the
Purchaser shall use their respective best efforts to cause at least three
members of the Company's Board of Directors at all times prior to the
Effective Time to be Continuing Directors. "Continuing Director" means (a) any
member of the Company's Board of Directors on the date of the Merger
Agreement, (b) any member of the Company's Board of Directors who is not an
employee or director or affiliate of, and not a Designated Director or other
nominee of, the Purchaser or CertainTeed or their respective subsidiaries, and
(c) any successor of a Continuing Director who is (i) not an employee or
director or affiliate of, and not a Designated Director or other nominee of,
the Purchaser or CertainTeed or their respective subsidiaries and (ii)
recommended to succeed such Continuing Director by at least a majority of the
then Continuing Directors.
 
  (9) Stock Options. The Merger Agreement provides that, with respect to
unexpired Stock Options, whether or not exercisable at the Effective Date,
including stock appreciation rights relating thereto, outstanding on the
Effective Date which have been issued pursuant to the 1982 Stock Option Plan,
the 1992 Stock Option Plan, or the Director Option Plan, each such Stock
Option with an exercise price less than the Common Price (an "Eligible
Option") shall, by virtue of the Merger and without any action on the part of
the holder thereof, be converted into the right to receive, for each Common
Share subject thereto, a cash payment without interest equal to the Common
Price, less the per share exercise price of each such Stock Option. Such Stock
Options will be canceled upon such cash payment following the Merger. Any
Stock Option with an exercise price equal to or greater than the Common Price
(an "Ineligible Option") shall be canceled upon the Effective Date without
payment of any consideration. The Merger Agreement requires the Company to use
its best efforts to amend each outstanding Stock Option issued under the 1982
Stock Option Plan, the 1992 Stock Option Plan and the Director Option Plan to
effect the transactions contemplated by the Merger Agreement, including the
cancellation of the Stock Options in connection with the Merger in accordance
with the foregoing. Each Common Share issued by the Company but not yet vested
pursuant to the Savings Plan shall, in connection with the Merger, become
vested in the person to whose account such Common Share was issued and
converted into the right to receive the Common Price pursuant to the Merger
Agreement.
 
  The Company has informed the Purchaser that, as of January 12, 1998, there
were no Common Shares held in escrow pursuant to the Company's former Long
Term Incentive Compensation Plan (the "LTIP"), and the LTIP has been
terminated. Immediately following the Effective Date, the Company's 1982
Option Plan, 1992 Option Plan and Director Option Plan shall be terminated and
no further stock awards or stock options will be granted thereunder from and
after the date of the Merger Agreement.
 
  (10) Indemnification and Insurance. In the Merger Agreement, CertainTeed and
the Purchaser have agreed that all rights to indemnification in existence as
of the date of the Merger Agreement in favor of the directors or officers of
the Company and its subsidiaries (the "Indemnified Parties") as currently
provided in their respective certificates or articles of incorporation or
organization and by-laws or in any agreements, contracts or arrangements with
the Company or any of its subsidiaries in effect as of the date of the Merger
Agreement and previously furnished to CertainTeed and to the extent not in
violation of applicable state law, shall survive the Merger and shall continue
in full force and effect for a period of five years from the Effective Date;
provided
 
                                      25

 
that, in the event any claim or claims are asserted or made within such five
year period, all rights to indemnification in respect of any such claim or
claims shall continue until the disposition of any and all such claims. In
addition, the Merger Agreement provides that, to the extent currently provided
in the certificates or articles of incorporation or organization and by-laws
of the Company and its subsidiaries and Massachusetts law, or agreements,
contracts or arrangements disclosed to CertainTeed with the Company or any of
the subsidiaries, in the event that any Indemnified Party becomes involved in
any capacity in any action, proceeding or investigation in connection with any
matter, including the transaction contemplated by the Merger Agreement,
occurring prior to, and including, the Effective Date, or otherwise relating
to or arising out of such matters, CertainTeed or the Surviving Corporation
will periodically advance to such Indemnified Party his or her legal and other
expenses (including the costs of any investigation and preparation incurred in
connection therewith).
 
  The Merger Agreement provides that CertainTeed will use all reasonable
efforts to maintain in effect, or shall cause the Surviving Corporation to use
all reasonable efforts to maintain in effect, for two years after the
Effective Date, directors' and officers' liability insurance ("D&O Insurance")
covering those persons covered by the Company's directors' and officers'
liability insurance on the date of the Merger Agreement or the Effective Date
and which is substantially equivalent in terms of coverage and amount as the
Company has in effect on the Effective Date so long as such insurance is
available and the annual premium therefor would not be in excess of $166,000
(the "Maximum Premium"). If the existing D&O Insurance expires, is terminated
or cancelled during such two-year period, CertainTeed shall use all reasonable
efforts to cause to be obtained as much D&O Insurance as can be obtained for
the remainder of such period for an annualized premium not in excess of the
Maximum Premium, on terms and conditions no less advantageous than the
existing D&O Insurance.
 
  The Merger Agreement further provides that (a) any Indemnified Party wishing
to claim indemnification pursuant to the Merger Agreement, upon learning of
any legal action, suit, investigation, inquiry or proceeding by any
governmental authority or other person, shall promptly notify CertainTeed and
the Surviving Corporation with respect thereto, but the failure to so notify
shall not relieve CertainTeed or the Surviving Corporation of any liability it
may have to such Indemnified Party under the Merger Agreement except to the
extent that CertainTeed and the Surviving Corporation are materially
prejudiced thereby, (b) CertainTeed and the Surviving Corporation shall
periodically, as requested, advance to such Indemnified Party his, her or its
legal and other expenses (including the cost of investigation and preparation
incurred in connection therewith) to the extent such Indemnified Party is
indemnified pursuant to the Merger Agreement, unless it is ultimately
determined by a court of competent jurisdiction that such Indemnified Party is
not entitled to indemnification hereunder, and (c) CertainTeed and the
Surviving Corporation shall be subrogated to any rights any Indemnified Party
may have with respect to any amounts paid to or on behalf of such Indemnified
Party by CertainTeed and the Surviving Corporation pursuant to the Merger
Agreement.
 
  (11) Representations and Warranties. The Merger Agreement contains various
customary representations and warranties. The Merger Agreement requires that
CertainTeed, the Purchaser and the Company shall each take such action as is
reasonably necessary to render their respective representations and warranties
accurate on and as of the Effective Date. Without limiting the foregoing, the
Merger Agreement provides that the Company shall take any action required by
CertainTeed to ensure the accuracy of its representations pertaining to
Massachusetts' anti-takeover laws.
 
 The Stockholder Agreement
 
  Pursuant to the Stockholder Agreement, the directors (the "Selling
Stockholders") of the Company have unconditionally agreed to tender into the
Offer, and not to withdraw therefrom, the 1,670,657 Common Shares and 132,200
Preference Shares that they owned on January 12, 1998, together with any
Shares they acquire after such time, including upon the exercise of Stock
Options. In addition, the Selling Stockholders have agreed to sell to the
Purchaser, and the Purchaser has agreed to purchase, the foregoing number of
Common Shares at a price per Common Share of $5.50, or such higher price per
Common Share as may be offered by the Purchaser in the Offer and Preference
Shares at a price per Preference Share of $20.00, or such higher price per
Preference
 
                                      26

 
Share as may be offered by the Purchaser in the Offer, provided that (i) such
obligation to purchase is subject to (a) the Purchaser having accepted Common
Shares and Preference Shares for payment under the Offer or (b) if the Offer
has been terminated for failure to satisfy the Minimum Condition, (i) all
conditions to the Offer (other than the Minimum Condition) having been
satisfied and (ii) including all Common Shares and Preference Shares tendered
and not withdrawn at the time of termination of the Offer and all Shares to be
purchased pursuant to the Stockholder Agreement, the Minimum Condition would
have been satisfied. Notwithstanding the foregoing, no Selling Stockholder
shall be obligated to sell his or her Shares after the scheduled final
expiration time of the Offer unless (i) the Minimum Condition was not
satisfied, (ii) such Selling Stockholder did not tender such Stockholder's
Shares into the Offer or withdrew such Shares and (iii) including all Common
Shares and Preference Shares tendered and not withdrawn at the time of
termination of the Offer and all Shares to be purchased pursuant to the
Stockholder Agreement, the Minimum Condition would have been satisfied. The
Shares subject to the Stockholder Agreement represent approximately 40.2% of
the Common Shares and 16.2% of the Preference Shares.
 
  Each of the Selling Stockholders has agreed not to: (i) sell, transfer,
pledge, assign or otherwise dispose of, or enter into any contract, option or
other arrangement (including any profit sharing arrangement) or understanding
with respect to the sale, transfer, pledge, assignment or other disposition
of, his or her Shares to any person other than the Purchaser or the
Purchaser's designee, (ii) enter into any voting arrangement, whether by
proxy, voting agreement, voting trust, power-of-attorney or otherwise, with
respect to his or her Shares or (iii) take any other action that would in any
way restrict, limit or interfere with the performance of its obligations
hereunder or the transactions contemplated hereby. Each of the Selling
Stockholders has also agreed not to solicit, initiate or encourage (including
by way of furnishing information) and not to participate in any discussions or
negotiations regarding any takeover proposal (as defined in the Merger
Agreement).
 
  Under the Stockholder Agreement, each Selling Stockholder has granted an
irrevocable proxy with respect to the Shares subject to the Stockholder
Agreement to CertainTeed to vote such Shares against (i) any merger agreement
or merger (other than the Merger Agreement and the Merger), consolidation,
combination, sale of substantial assets, reorganization, joint venture,
recapitalization, dissolution, liquidation or winding up of or by the Company
and (ii) any amendment of the Company's articles of incorporation or its by-
laws, or other proposal or transactions (including any consent solicitation to
remove or elect any directors of the Company) involving the Company, which
amendment or other proposal or transaction would in any manner impede,
frustrate, prevent or nullify, or result in a breach of any covenant,
representation or warranty or any other obligation or agreement of the Company
under or with respect to, the Offer, the Merger, the Merger Agreement or any
of the transactions contemplated by the Merger Agreement.
 
  The foregoing summary of the Stockholder Agreement is qualified in its
entirety by reference to the Stockholder Agreement, a copy of which is filed
as Exhibit (c)(2) to the Schedule 14D-1. The Stockholder Agreement should be
read in its entirety for a more complete description of the matters summarized
above.
 
  Plans for the Company. Saint-Gobain and its affiliates currently intend that
the Company will continue its present manufacturing operations in
Massachusetts and will continue to operate under its present corporate name,
as a wholly owned subsidiary of CertainTeed. CertainTeed has had preliminary
discussions with Richard C. Maloof, the President of the Company, and Frank S.
Anthony, Vice President, General Counsel and Corporate Secretary of the
Company, regarding their continued employment with the Surviving Corporation
on terms which have yet to be decided, but these discussions have not yet
resulted in any commitments by any of the parties.
 
  Except as otherwise described in this Offer to Purchase, none of the
Purchaser, CertainTeed or Saint-Gobain has any current plans or proposals that
relate to, or would result in, any extraordinary corporate transaction
involving the Company, such as a merger, reorganization or liquidation
involving the Company or any of its subsidiaries to any unaffiliated third
party.
 
  Appraisal Rights. Holders of Shares do not have appraisal rights as a result
of the Offer. However, if the Merger is consummated, holders of outstanding
Common Shares, Preference Shares and 5% Stock on the Effective Date will have
certain rights pursuant to the provisions of Sections 85 through 98,
inclusive, of the
 
                                      27

 
MBCL to dissent and demand appraisal of their shares. Under Sections 85
through 98, inclusive, of the MBCL, dissenting stockholders who comply with
the applicable statutory procedures will be entitled to receive a judicial
determination of the fair value of their shares (exclusive of any element of
value arising from the accomplishment or expectation of the Merger) and to
receive payment of such fair value in cash, together with a fair rate of
interest, if any. Any such judicial determination of the fair value of shares
could be based upon factors other than, or in addition to, the price per share
to be paid in the Merger or the market value of the shares. The value so
determined could be more or less than the price per share to be paid in the
Merger.
 
  The foregoing summary of Sections 85 through 98, inclusive, of the MBCL does
not purport to be complete and is qualified in its entirety by reference to
Sections 85 through 98, inclusive, of the MBCL. Failure to follow the steps
required by Sections 85 through 98, inclusive, of the MBCL for perfecting
appraisal rights may result in the loss of such rights.
 
  Going Private Transactions. The SEC has adopted Rule 13e-3 under the
Exchange Act which is applicable to certain "going private" transactions. The
Purchaser does not believe that Rule 13e-3 will be applicable to the Merger
unless the Merger is consummated more than one year after the termination of
the Offer. If applicable, Rule 13e-3 requires, among other things, that
certain financial information concerning the fairness of the Merger and the
consideration offered to minority stockholders in such transaction be filed
with the SEC and disclosed to stockholders prior to the consummation of the
Merger.
 
13. DIVIDENDS AND DISTRIBUTIONS
 
  Pursuant to the terms of the Merger Agreement, the Company is prohibited
from taking any of the actions described in the two succeeding paragraphs, and
nothing herein shall constitute a waiver by the Purchaser or CertainTeed of
any of its rights under the Merger Agreement or a limitation of remedies
available to the Purchaser or CertainTeed for any breach of the Merger
Agreement, including termination thereof.
 
  If, on or after January 12, 1998, the Company should (a) split, combine or
otherwise change the Shares or its capitalization, (b) acquire or otherwise
cause a reduction in the number of outstanding Shares or other securities
(other than as aforesaid) or (c) issue or sell additional Shares (other than
the issuance of Common Shares under option prior to January 12, 1998, in
accordance with the terms of such options as publicly disclosed prior to
January 12, 1998, shares of any other class of capital stock, other voting
securities or any securities convertible into, or rights, warrants or options,
conditional or otherwise, to acquire, any of the foregoing, then, subject to
the provisions of Section 14, the Purchaser, in its sole discretion, may make
such adjustments as it deems appropriate in the Common Price, the Preference
Price and other terms of the Offer, including, without limitation, the number
or type of securities offered to be purchased.
 
  If, on or after January 12, 1998, the Company should declare or pay any cash
dividend on the Common Shares or Preference Shares (including any accrued and
previously unpaid dividends) or other distribution on the Shares, or issue
with respect to the Shares or any additional Shares, shares of any other class
of capital stock, other voting securities or any securities convertible into,
or rights, warrants or options, conditional or otherwise, to acquire, any of
the foregoing, payable or distributable to stockholders of record on a date
prior to the transfer of the Shares purchased pursuant to the Offer to the
Purchaser or its nominee or transferee on the Company's stock transfer
records, then, subject to the provisions of Section 14, (a) the Common Price
and/or the Preference Price may, in the sole discretion of the Purchaser, be
reduced by the amount of any such cash dividend or cash distribution and (b)
the whole of any such noncash dividend, distribution or issuance to be
received by the tendering stockholders will (i) be received and held by the
tendering stockholders for the account of the Purchaser and will be required
to be promptly remitted and transferred by each tendering stockholder to the
Depositary for the account of the Purchaser, accompanied by appropriate
documentation of transfer, or (ii) at the direction of the Purchaser, be
exercised for the benefit of the Purchaser, in which case the proceeds of such
exercise will promptly be remitted to the Purchaser. Pending such remittance
and subject to applicable law, the Purchaser will be entitled to all rights
and privileges as owner of any such noncash dividend, distribution, issuance
or proceeds and may withhold the entire Common Price and/or Preference Price
or deduct from the
 
                                      28

 
Common Price and/or the Preference Price the amount or value thereof, as
determined by the Purchaser in its sole discretion.
 
  The Merger Agreement provides that the Company shall not declare and pay or
set apart for payment any accumulated dividends on the Common Shares, the 5%
Stock or the Preference Shares. Accordingly the Company will not declare the
February 15, 1998 dividend on the Preference Shares or the March 1, 1998
dividend on the 5% Stock.
 
14. CERTAIN CONDITIONS OF THE OFFER
 
  Notwithstanding any other term of the Offer or the Merger Agreement, the
Purchaser shall not be required to accept for payment or, subject to any
applicable rules and regulations of the SEC, including Rule 14e-1(c) under the
Exchange Act (relating to Purchaser's obligation to pay for or return tendered
Shares after the termination or withdrawal of the Offer), to pay for any
Shares tendered pursuant to the Offer unless the Minimum Condition, the HSR
Condition and the Required Consents Condition shall all have been satisfied.
Furthermore, notwithstanding any other term of the Offer or the Merger
Agreement, the Purchaser shall not be required to accept for payment or,
subject as aforesaid, to pay for any Shares not theretofore accepted for
payment or paid for, and may terminate the Offer if, at any time on or after
the date of the Merger Agreement and before the Consummation of the Offer any
of the following conditions exist:
 
    (a) the representations and warranties of the Company contained in the
  Merger Agreement (without regard to any supplemental information provided
  pursuant to the Merger Agreement) that are qualified as to materiality
  shall not be true and correct, and the representations that are not so
  qualified shall not be true and correct in all material respects, in each
  case on and as of the date of the Merger Agreement and on and as of the
  Expiration Date;
 
    (b) any of the obligations of the Company to be performed by it on or
  before the Expiration Date pursuant to the terms of the Merger Agreement
  shall not have been duly performed or complied with in all material
  respects by that date;
 
    (c) since September 30, 1997, there shall have occurred (or it shall be
  reasonably expected that there will be) any event, change or circumstance
  causing, or reasonably anticipated to cause in the future, any Material
  Adverse Effect;
 
    (d) any consents, approvals and authorizations from third persons and
  governmental authorities identified in the Merger Agreement required to
  consummate the transactions contemplated by the Merger Agreement shall not
  have been obtained;
 
    (e) there shall be pending or threatened any suit, action or proceeding
  by any governmental authority (i) challenging the acquisition by
  CertainTeed or the Purchaser of any Shares, seeking to restrain or prohibit
  the consummation of the Offer, the Merger or any of the other transactions
  contemplated by the Merger Agreement or seeking to obtain from the Company,
  CertainTeed or the Purchaser any damages related to the Offer, the Merger
  or any of the other transactions contemplated by the Merger Agreement that
  are material in relation to the Company and its subsidiaries taken as a
  whole, (ii) seeking to prohibit or limit the ownership or operation by the
  Company, CertainTeed or any of their respective subsidiaries of any
  material portion of the business or assets of the Company, CertainTeed or
  any of their respective subsidiaries, or to compel the Company, CertainTeed
  or any of their respective subsidiaries to dispose of or hold separate any
  material portion of the business or assets of the Company, CertainTeed or
  any of their respective subsidiaries, as a result of the Offer, the Merger
  or any of the other transactions contemplated by the Merger Agreement,
  (iii) seeking to impose limitations on the ability of CertainTeed or the
  Purchaser to acquire or hold, or exercise full rights of ownership of, any
  common stock of the Surviving Corporation, (iv) seeking to prohibit
  CertainTeed or any of its subsidiaries from effectively controlling in any
  material respect the business or operations of the Company or its
  subsidiaries or of CertainTeed and its subsidiaries or (v) which otherwise
  is reasonably likely to have a Material Adverse Effect;
 
    (f) there shall be any statute, rule, regulation, judgment, order or
  injunction enacted, entered, enforced, promulgated or deemed applicable to
  the Offer or the Merger, or any other action shall be taken by any
  governmental authority or court, other than the application to the Offer or
  the Merger of applicable waiting
 
                                      29

 
  periods under the HSR Act, that is reasonably likely to result, directly or
  indirectly, in any of the consequences referred to in clauses (i) through
  (v) of paragraph (e) above;
 
    (g) the Company's Board or any committee thereof shall have withdrawn or
  modified in a manner adverse to CertainTeed its approval or recommendation
  of the Offer, the Merger or the Merger Agreement or resolved to take any of
  such actions; or
 
    (h) the Merger Agreement shall have been terminated in accordance with
  its terms.
 
  The foregoing conditions are for the sole benefit of the Purchaser and
CertainTeed and may, subject to the terms of the Merger Agreement, be waived
by the Purchaser and CertainTeed in whole or in part at any time and from time
to time. The failure by CertainTeed or the Purchaser at any time to exercise
any of the foregoing rights shall not be deemed a waiver of any such right,
the waiver of any such right with respect to particular facts and
circumstances shall not be deemed a waiver with respect to any other facts and
circumstances, and each such right shall be deemed an ongoing right that may
be asserted at any time and from time to time.
 
15. CERTAIN LEGAL MATTERS
 
  Except as described in this Section 15, based on a review of publicly
available filings made by the Company with the SEC and other publicly
available information concerning the Company, none of the Purchaser,
CertainTeed or Saint-Gobain is aware of any license or regulatory permit that
appears to be material to the business of the Company and its subsidiaries,
taken as a whole, that might be adversely affected by the Purchaser's
acquisition of Shares (and the indirect acquisition of the stock of the
Company's subsidiaries) as contemplated herein or of any approval or other
action by any governmental entity that would be required or desirable for the
acquisition or ownership of Shares by the Purchaser as contemplated herein.
Should any such approval or other action be required or desirable, the
Purchaser, CertainTeed, and Saint-Gobain currently contemplate that such
approval or other action will be sought, except as described below under
"State Takeover Laws." While, except as otherwise expressly described in this
Section 15, the Purchaser does not presently intend to delay the acceptance
for payment of or payment for Shares tendered pursuant to the Offer pending
the outcome of any such matter, there can be no assurance that any such
approval or other action, if needed, would be obtained or would be obtained
without substantial conditions or that failure to obtain any such approval or
other action might not result in consequences adverse to the Company's
business or that certain parts of the Company's business might not have to be
disposed of if such approvals were not obtained or such other actions were not
taken or in order to obtain any such approval or other action. If certain
types of adverse action are taken with respect to the matters discussed below,
the Purchaser could decline to accept for payment or pay for any Shares
tendered. See Section 14 for certain conditions to the Offer.
 
  State Takeover Laws. A number of states throughout the United States have
enacted takeover statutes that purport, in varying degrees, to be applicable
to attempts to acquire securities of corporations that are incorporated or
have assets, stockholders, executive offices or places of business in such
states. In Edgar v. MITE Corp., the Supreme Court of the United States held
that the Illinois Business Takeover Act, which involved state securities laws
that made the takeover of certain corporations more difficult, imposed a
substantial burden on interstate commerce and therefore was unconstitutional.
In CTS Corp. v. Dynamics Corp. of America, however, the Supreme Court of the
United States held that a state may, as a matter of corporate law and, in
particular, those laws concerning corporate governance, constitutionally
disqualify a potential acquiror from voting on the affairs of a target
corporation without prior approval of the remaining stockholders, provided
that such laws were applicable only under certain conditions. Subsequently, a
number of Federal courts ruled that various state takeover statutes were
unconstitutional insofar as they apply to corporations incorporated outside
the state of enactment.
 
  Except as described herein, the Purchaser has not attempted to comply with
any state takeover statutes in connection with the Offer. The Purchaser
reserves the right to challenge the validity or applicability of any state law
allegedly applicable to the Offer and nothing in this Offer to Purchase nor
any action taken in connection herewith is intended as a waiver of that right.
In the event that any state takeover statute is found applicable to
 
                                      30

 
the Offer, the Purchaser might be unable to accept for payment or pay for
Shares tendered pursuant to the Offer or be delayed in continuing or
consummating the Offer. In such case, the Purchaser might not be obligated to
accept for payment or pay for any Shares tendered. See Section 14.
 
  Massachusetts Statutes. Massachusetts has enacted a Business Combination
Statute that, in general, prohibits any business combination between a widely
held Massachusetts corporation and an interested stockholder for three years
after that person becomes an interested (i.e., 5%) stockholder unless: (a)
prior to the date that person becomes an interested stockholder, the board of
directors of the corporation approved either the transaction that made the
acquiror an interested stockholder or the proposed business combination; (b)
upon consummation of the transaction that made the acquiror an interested
stockholder, the acquiror owns at least 90 percent of the voting stock,
excluding shares held by directors, officers and employee stock plans in which
employee participants do not have the right to determine confidentially
whether shares held by the plan will be tendered; or (c) at or subsequent to
the time the acquiror becomes an interested stockholder, the board of
directors of the corporation and holders of two-thirds of the shares of voting
stock not held by interested stockholders approve the business combination.
Massachusetts has also enacted a Control Share Acquisition Statute that
provides, in general, that shares of a widely-held Massachusetts corporation
acquired in a Control Share Acquisition (as defined in the statute) will not
have voting rights unless, among other things, voting rights for such shares
are approved by a vote of stockholders of the corporation, not including those
holding such shares. Excluded from the definition of "Control Share
Acquisition" is, among other things, an acquisition by merger or tender offer
pursuant to a merger agreement to which the Massachusetts corporation is a
party. Massachusetts has also enacted a Take-Over Bid Statute that imposes
certain procedural requirements and prohibitions in connection with a Take-
Over Bid (as defined in the statute).
 
  PURSUANT TO MASSACHUSETTS LAW, THE COMPANY HAS TAKEN ALL NECESSARY STEPS TO
RENDER THE MASSACHUSETTS BUSINESS COMBINATION STATUTE, CONTROL SHARE
ACQUISITION STATUTE AND TAKE-OVER BID STATUTE INAPPLICABLE TO THE ACQUISITION
OF SHARES IN THE OFFER OR THE MERGER.
 
  Antitrust. Under the provisions of the HSR Act applicable to the Offer, the
acquisition of Shares under the Offer may be consummated following the
expiration of a 15-calendar day waiting period following the filing by Saint-
Gobain of a Notification and Report Form with respect to the Offer, unless
Saint-Gobain receives a request for additional information or documentary
material from the Antitrust Division or the FTC or unless early termination of
the waiting period is granted. Saint-Gobain made such filing on January 15,
1998. If, within the initial 15-day waiting period, either the Antitrust
Division or the FTC requests additional information or material from Saint-
Gobain concerning the Offer, the waiting period will be extended and would
expire at 11:59 p.m., New York City time, on the tenth calendar day after the
date of substantial compliance by Saint-Gobain with such request. Only one
extension of the waiting period pursuant to a request for additional
information is authorized by the HSR Act. Thereafter, such waiting period may
be extended only by court order or with the consent of Saint-Gobain. In
practice, complying with a request for additional information or material can
take a significant amount of time. In addition, if the Antitrust Division or
the FTC raises substantive issues in connection with a proposed transaction,
the parties frequently engage in negotiations with the relevant governmental
agency concerning possible means of addressing those issues and may agree to
delay consummation of the transaction while such negotiations continue.
Expiration or termination of the applicable waiting period under the HSR Act
is a condition to the Purchaser's obligation to accept for payment and pay for
Shares tendered pursuant to the Offer.
 
  The Antitrust Division and the FTC frequently scrutinize the legality under
the antitrust laws of transactions such as the Purchaser's proposed
acquisition of the Company. At any time before or after the Purchaser's
acquisition of Shares pursuant to the Offer, the Antitrust Division or the FTC
could take such action under the antitrust laws as it deems necessary or
desirable in the public interest, including seeking to enjoin the purchase of
Shares pursuant to the Offer or the consummation of the Merger or seeking the
divestiture of Shares acquired by the Purchaser or the divestiture of
substantial assets of the Company or its subsidiaries or Saint-Gobain or its
subsidiaries. Private parties may also bring legal action under the antitrust
laws under certain circumstances. There can be no assurance that a challenge
to the Offer on antitrust grounds will not be made or, if such a challenge is
made, of the result thereof.
 
 
                                      31

 
16. FEES AND EXPENSES
 
  McFarland Dewey is acting as Dealer Manager in connection with the Offer and
is providing certain financial advisory services to CertainTeed in connection
with the Offer. CertainTeed has agreed to pay McFarland Dewey as compensation
for such services (i) financial advisory and other related fees aggregating
$400,000, which are payable or become payable upon the consummation of the
transactions contemplated by the Offer and (ii) a dealer manager fee of
$100,000 payable upon commencement of the Offer. CertainTeed has also agreed
to reimburse McFarland Dewey for its out-of-pocket expenses, including the
reasonable fees and expenses of its counsel and any other advisor retained by
McFarland Dewey, in connection with its engagement and to indemnify McFarland
Dewey and certain related persons against certain liabilities and expenses,
including certain liabilities and expenses under the Federal securities laws.
 
  The Purchaser has retained Georgeson & Company Inc. to act as the
Information Agent and ChaseMellon Shareholder Services, L.L.C. to serve as the
Depositary in connection with the Offer. The Information Agent and the
Depositary each will receive reasonable and customary compensation for their
services, be reimbursed for certain reasonable out-of-pocket expenses and be
indemnified against certain liabilities and expenses in connection therewith,
including certain liabilities and expenses under the Federal securities laws.
 
  None of the Purchaser, CertainTeed or Saint-Gobain will pay any fees or
commissions to any broker or dealer or other person (other than the Dealer
Manager and the Information Agent) in connection with the solicitation of
tenders of Shares pursuant to the Offer. Brokers, dealers, banks and trust
companies will be reimbursed by the Purchaser upon request for customary
mailing and handling expenses incurred by them in forwarding material to their
customers.
 
17. MISCELLANEOUS
 
  The Offer is not being made to (nor will tenders be accepted from or on
behalf of) holders of Shares in any jurisdiction in which the making of the
Offer or the acceptance thereof would not be in compliance with the laws of
such jurisdiction. None of the Purchaser, CertainTeed or Saint-Gobain is aware
of any jurisdiction in which the making of the Offer or the acceptance thereof
would not be in compliance with the laws of such jurisdiction. To the extent
the Purchaser, CertainTeed or Saint-Gobain becomes aware of any state law that
would limit the class of offerees in the Offer, the Purchaser will amend the
Offer and, depending on the timing of such amendment, if any, will extend the
Offer to provide adequate dissemination of such information to holders of
Shares prior to the expiration of the Offer. In any jurisdiction the
securities, blue sky or other laws of which require the Offer to be made by a
licensed broker or dealer, the Offer is being made on behalf of the Purchaser
by the Dealer Manager or one or more registered brokers or dealers licensed
under the laws of such jurisdiction.
 
  NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATION ON BEHALF OF THE PURCHASER, CERTAINTEED OR SAINT-GOBAIN NOT
CONTAINED IN THIS OFFER TO PURCHASE OR IN THE LETTER OF TRANSMITTAL AND, IF
GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATION MUST NOT BE RELIED UPON AS
HAVING BEEN AUTHORIZED.
 
  The Purchaser, CertainTeed and Saint-Gobain have filed with the SEC a
Schedule 14D-1 pursuant to Rule 14d-3 under the Exchange Act, together with
exhibits, furnishing certain additional information with respect to the Offer,
and may file amendments thereto. In addition, the Company has filed the
Schedule 14D-9 pursuant to Rule 14d-9 under the Exchange Act, together with
exhibits setting forth its recommendation with respect to the Offer and the
reasons for such recommendation and furnishing such additional related
information. Such Schedules and any amendments thereto, including exhibits,
should be available for inspection and copies should be obtainable in the
manner set forth in Section 8 (except that such material will not be available
at the regional offices of the SEC).
 
                                                          BI EXPANSION II CORP.
 
January 16, 1998
 
                                      32

 
                                  SCHEDULE I
 
     DIRECTORS AND EXECUTIVE OFFICERS OF SAINT-GOBAIN, CERTAINTEED AND THE
                                   PURCHASER
 
DIRECTORS AND EXECUTIVE OFFICERS OF COMPAGNIE DE SAINT-GOBAIN
 
  The following table sets forth the name, business address, and present
principal occupation or employment and five-year employment history of the
directors and executive officers of Compagnie de Saint-Gobain. All directors
and officers of Compagnie de Saint-Gobain listed below are citizens of France
except for Mr. Breuer, who is a citizen of Germany, Mr. Dachowski, who is a
citizen of the United Kingdom, and Messrs. Caccini and Caliari, who are
citizens of Italy. Directors are indicated by an asterisk.
 


                                       PRESENT PRINCIPAL OCCUPATION OR
          NAME AND                              EMPLOYMENT AND
      BUSINESS ADDRESS                   FIVE-YEAR EMPLOYMENT HISTORY
      ----------------                 -------------------------------
                           
Jean-Louis Beffa*...........  Chairman and Chief Executive Officer of Compagnie
 Compagnie de Saint-Gobain    de Saint-Gobain (1992-present)
 Les Miroirs
 92096 La Defense Cedex
 (France)
Claude Bebear*..............  Chairman of the Management Board of AXA-UAP (1997-
 AXA-UAP                      present); Chairman and Chief Executive Officer of
 23 rue Matignon              AXA Group (1992-1997)
 75008 Paris (France)
Dr. Rolf E. Breuer*.........  Chairman of the Management Board of Deutsche Bank
 Deutsche Bank                (1997-present); Member of the Management Board of
 Taunusanlage 12              Deutsche Bank (1992-present)
 60262 Frankfurt (Germany)
Gilles de Cambronne*........  Deputy Manager at the Direction of the Legal and
 Compagnie de Saint-Gobain    Tax Departments of Compagnie de Saint-Gobain
 Les Miroirs                  (1992-present)
 92096 La Defense Cedex
 (France)
Guy Dejouany*...............  Honorary Chairman and Director of Compagnie
 Compagnie Generale des Eaux  Generale des Eaux (1996-present); Chairman and
 52 rue d'Anjou               Chief Executive Officer of Compagnie Generale des
 75008 Paris (France)         Eaux (1992-1996)
Bernard Esambert*...........  Vice-Chairman of the Bollore Group (1992-present)
 Groupe Bollore
 51-52 quai de Dion-Bouton
 92811 Puteaux (France)
Pierre Faurre*..............  Chairman and Chief Executive Officer of SAGEM
 SAGEM                        (1992-present)
 6 avenue d'Iena
 75783 Paris Cedex (France)
Olivier Lecerf*.............  Honorary Chairman of Societe Lafarge (1992-
 Societe Lafarge (Retired)    present); Director of Societe Lafarge (1992-
 28 rue Emile Menier          present)
 75116 Paris (France)
Jacques-Louis Lions*........  Professor of the College de France (Paris) (1992-
 College de France            present); President of the French Academy of
 3 rue d'Ulm                  Sciences (1996-present)
 75005 Paris (France)

 
                                      S-1

 


                                       PRESENT PRINCIPAL OCCUPATION OR
          NAME AND                              EMPLOYMENT AND
      BUSINESS ADDRESS                   FIVE-YEAR EMPLOYMENT HISTORY
      ----------------                 -------------------------------
                           
Jean-Maurice Malot*.........  President of the Employees' and Former Employees'
 Saint-Gobain Vitrage         Shareholders Association of Compagnie de Saint-
 BP 50                        Gobain (1997-present); Manager of the French
 33230 Coutras (France)       Southern and Western subsidiaries of the Flat
                              Glass Division of Compagnie de Saint-Gobain (1992-
                              present)
Jean-Marie Messier*.........  Chairman and Chief Executive Officer of Compagnie
 Compagnie Generale des Eaux  Generale des Eaux (1996-present); Chairman of the
 52 rue d'Anjou               Executive Committee of Compagnie Generale des Eaux
 75008 Paris (France)         (1994-1996); Managing Partner of Lazard Freres &
                              Cie (1992-1994)
Gerard Mestrallet*..........  Chairman of the Management Board of Suez/Lyonnaise
 Suez/Lyonnaise des Eaux      des Eaux (1997-present); Chairman and Chief
 1 rue d'Astorg               Executive Officer of Compagnie de Suez (1995-
 75008 Paris (France)         1997); Executive Officer of Societe Generale de
                              Belgique (1992-1995)
Eric Monnier*...............  Employee of Compagnie de Saint-Gobain (1992-
 Compagnie de Saint-Gobain    present)
 Les Miroirs
 92096 La Defense Cedex
 (France)
Michael Pebereau*...........  Chairman and Chief Executive Officer of Banque
 Banque Nationale de Paris    Nationale de Paris (1992-present)
 16 boulevard des Italiens
 75009 Paris (France)
Bruno Roger*................  Managing Director of Lazard Freres & Cie. (1992-
 Lazard Freres & Cie.         present);
 121 boulevard Haussmann      Managing Partner of Lazard Freres & Cie. (1992-
 75008 Paris (France)         present)
Eric d'Hautefeuille.........  Senior Vice President of Compagnie de Saint-Gobain
 Compagnie de Saint-Gobain    (1996-present); President of the Flat Glass
 Les Miroirs                  Division of Compagnie de Saint-Gobain (1992-1996)
 92096 La Defense Cedex
 (France)
Gianpaolo Caccini...........  Vice Chairman, President and Chief Executive
 Saint-Gobain Corporation     Officer of Saint-Gobain Corporation (1996-
 750 East Swedesford Road     present); Chairman, President, Chief Executive
 Valley Forge, Pennsylvania   Officer and Director of CertainTeed Corporation
 19482                        (1996-present); Senior Vice President and General
                              Delegate for the United States and Canada of
                              Compagnie de Saint-Gobain (1996-present);
                              President of the Fiber Reinforcement Division of
                              Compagnie de Saint-Gobain (1993-1996); President
                              of the Insulation Division of Compagnie de Saint-
                              Gobain (1992-1993)
Jean-Gerard Claudon*........  Senior Vice President of Compagnie de Saint-Gobain
 Poliet                       (1996-present); Chairman of the Supervisory Board
 Les Miroirs                  of Poliet (1997-present); Chairman of the
 92096 La Defense Cedex       Management Board of Poliet (1992-1997)
 (France)
Emile Francois..............  Senior Vice President of Compagnie de Saint-Gobain
 Compagnie de Saint-Gobain    (1997-present); Chairman of the Management Board
 Les Miroirs                  of Poliet (1997-present); Chairman and Chief
 92096 La Defense Cedex       Executive Officer of Lapeyre (1997-present);
 (France)                     President of the Industrial Ceramics Division of
                              Compagnie de Saint-Gobain (1992-1996)

 
                                      S-2

 


                                      PRESENT PRINCIPAL OCCUPATION OR
          NAME AND                        EMPLOYMENT AND FIVE-YEAR
      BUSINESS ADDRESS                       EMPLOYMENT HISTORY
      ----------------                -------------------------------
                          
Claude Picot................ Senior Vice President of Compagnie de Saint-Gobain
 Saint-Gobain Emballage      (1996-present); President of the Containers
 Les Miroirs                 Division of Compagnie de Saint-Gobain (1992-
 92096 La Defense Cedex      present)
 (France)
Jacques Aschenbroich........ President of the Flat Glass Division of Compagnie
 Compagnie de Saint-Gobain   de Saint-Gobain (1996-present); Chairman of the
 Les Miroirs                 Management Board of Vegla GmbH (1992-1996)
 92096 La Defense Cedex
 (France)
Roberto Caliari............. President of the Reinforcement Division of
 Compagnie de Saint-Gobain   Compagnie de Saint-Gobain (1996-present); Manager
 Les Miroirs                 of European and Korean Development of the Fiber
 92096 La Defense Cedex      Reinforcement Division of Compagnie de Saint-
 (France)                    Gobain (1992-1996)
Pierre-Andre de Chalendar... President of the Abrasvies Division of Compagnie
 Norton Company              de Saint-Gobain (1996-present); Vice President of
 1 New Bond Street           Saint-Gobain Corporation (1996-present); General
 Worcester, MA 01615         Manager of Abrasives Europe of Compagnie de Saint-
                             Gobain (1993-1996); Vice President and General
                             Manager of Abrasives Europe of Compagnie de Saint-
                             Gobain (1992-1993)
Gilles Colas................ President of the Building Materials Division of
 Compagnie de Saint-Gobain   Compagnie de Saint-Gobain (1997-present);
 Les Miroirs                 Corporate Planning Director of Compagnie de Saint-
 92096 La Defense Cedex      Gobain (1992-1997)
 (France)
Philippe Crouzet............ President of the Industrial Ceramics Division of
 Compagnie de Saint-Gobain   Compagnie de Saint-Gobain (1996-present); General
 Les Miroirs                 Delegate for Spain and Portugal of Compagnie de
 92096 La Defense Cedex      Saint-Gobain (1992-1996)
 (France)
Peter R. Dachowski.......... President of the Insulation Division of Compagnie
 Compagnie de Saint-Gobain   de Saint-Gobain (1996-present); Executive Vice
 Les Miroirs                 President, Insulation of CertainTeed Corporation
 92096 La Defense Cedex      (1996-present); Executive Vice President of
 (France)                    CertainTeed Corporation (1994-1996); Senior Vice
                             President of CertainTeed Corporation (1992-1994);
                             Vice President of Saint-Gobain Corporation (1992-
                             present)
Christian Streiff........... President of the Pipe Division of Compagnie de
 Pont-a-Mousson SA           Saint-Gobain (1997-present); Managing Director of
 91 avenue de la Liberation  Saint-Gobain Emballage (1993-1997); Managing
 54000 Nancy (France)        Director of VETRI (1992-1993)
Bernard Field............... Corporate Secretary and Secretary of the Board of
 Compagnie de Saint-Gobain   Directors of Compagnie de Saint-Gobain (1992-
 Les Miroirs                 present)
 92096 La Defense Cedex
 (France)
Herve Gastinel.............. Corporate Planning Director of Compagnie de Saint-
 Compagnie de Saint-Gobain   Gobain (1998-present); Civil Services (1992-
 Les Miroirs                 present)
 92096 La Defense Cedex
 (France)

 
                                      S-3

 


                                      PRESENT PRINCIPAL OCCUPATION OR
          NAME AND                             EMPLOYMENT AND
      BUSINESS ADDRESS                  FIVE-YEAR EMPLOYMENT HISTORY
      ----------------                -------------------------------
                          
Jean-Paul Gelly............. Human Resources Director of Compagnie de Saint-
 Compagnie de Saint-Gobain   Gobain (1998-present); Managing Director of Saint-
 Les Miroirs                 Gobain Developpement (1992-1998)
 92096 La Defense Cedex
 (France)
Jean-Claude Lehman.......... Research Director of Compagnie de Saint-Gobain
 Compagnie de Saint-Gobain   (1992-present)
 Les Miroirs
 92096 La Defense Cedex
 (France)
Jean-Francois Phelizon...... Finance Director of Compagnie de Saint-Gobain
 Compagnie de Saint-Gobain   (1992-present)
 Les Miroirs
 92096 La Defense Cedex
 (France)
Pierre Tracol............... Director of International Development of Compagnie
 Compagnie de Saint-Gobain   de Saint-Gobain (1993-present); President of the
 Les Miroirs                 Fiber Reinforcements Division of Compagnie de
 92096 La Defense Cedex      Saint-Gobain (1992-1993)
 (France)

 
DIRECTORS AND EXECUTIVE OFFICERS OF CERTAINTEED CORPORATION
 
  The following table sets forth the name, present principal occupation or
employment and five-year employment history of the directors and executive
officers of CertainTeed Corporation. All directors and officers listed below
are citizens of the United States, except Mr. Caccini, who is a citizen of
Italy, and Mr. Dachowski, who is a citizen of the United Kingdom; and the
business address of each such person is 750 East Swedesford Road, Valley
Forge, Pennsylvania 19482, except where noted. Directors are indicated by an
asterisk.
 


                                      PRESENT PRINCIPAL OCCUPATION OR
                                               EMPLOYMENT AND
          NAME                          FIVE-YEAR EMPLOYMENT HISTORY
          ----                        -------------------------------
                      
Gianpaolo Caccini*...... Vice Chairman, President and Chief Executive Officer of
                         Saint-Gobain Corporation (1996-present); Chairman,
                         President, Chief Executive Officer and Director of
                         CertainTeed Corporation (1996-present); Senior Vice
                         President and General Delegate for the United States and
                         Canada of Compagnie de Saint-Gobain (1996-present);
                         President of the Fiber Reinforcement Division of
                         Compagnie de Saint-Gobain (1993-1996); President of the
                         Insulation Division of Compagnie de Saint-Gobain (1992-
                         1993)
Peter R. Dachowski...... President of the Insulation Division of Compagnie de
 Compagnie de Saint-     Saint-Gobain (1996-present); Executive Vice President,
 Gobain                  Insulation of CertainTeed Corporation (1996-present);
 Les Miroirs             Executive Vice President of CertainTeed Corporation
 92096 La Defense Cedex  (1994-1996); Senior Vice President of CertainTeed
 (France)                Corporation (1992-1994); Vice President of Saint-Gobain
                         Corporation (1992-present)
Lloyd C. Ambler......... President, Pipe & Plastics Group of CertainTeed
                         Corporation and Vice President of CertainTeed Corporation
                         (1992-present)
George B. Amoss*........ Vice President, Finance of Saint-Gobain Corporation and
                         CertainTeed Corporation (1994-present); Director of
                         CertainTeed Corporation (1997-present); Vice President
                         and Controller of Northern Telecom (1992-1994)

 
                                      S-4

 


                                   PRESENT PRINCIPAL OCCUPATION OR
                                           EMPLOYMENT AND
NAME                                FIVE-YEAR EMPLOYMENT HISTORY
- ----                               -------------------------------
 
                      
Dennis J. Baker......... Vice President of Saint-Gobain Corporation and
                         CertainTeed Corporation (1993-present); Vice President,
                         Human Resources of the Abrasives Division of Norton
                         Company (1992-present)
Bruce H. Cowgill........ Vice President of CertainTeed Corporation and President
                         of the Insulation Group of CertainTeed Corporation (1996-
                         present); Vice President and General Manager of the
                         Insulation Group of CertainTeed Corporation (1995-1996);
                         Vice President, Operations & Technology of the Insulation
                         Group of CertainTeed Corporation (1993-1995); Vice
                         President, Manufacturing of the Insulation Group of
                         CertainTeed Corporation (1992-1993)
Jean-Paul Dalle......... Vice President of CertainTeed Corporation (1996-present);
 Vetrotex CertainTeed    Director, President and Chief Operating Officer of
 Corporation             Vetrotex CertainTeed Corporation (1996-present); Vice
 4515 Allendale Road     President, Research and Development, Reinforcements
 Wichita Falls, TX 76310 Branch of Compagnie de Saint-Gobain (1993-1996); Vice
                         President, Manufacturing, Vetrotex International, S.A.
                         (Compagnie de Saint-Gobain) (1992-1993)
F. Lee Faust............ Vice President, Tax of Saint-Gobain Corporation and
                         CertainTeed Corporation (1993-present); Tax Counsel of
                         Phillips Petroleum (1992-1993)
Robert W. Fenton........ Vice President and Controller of Saint-Gobain Corporation
                         and CertainTeed Corporation (1996-present); Financial
                         Controller of Compagnie de Saint-Gobain (1995-1996);
                         Assistant Controller and Director of Financial Analysis
                         of Saint-Gobain Corporation and CertainTeed Corporation
                         (1993-1995); Director of Financial Analysis of Saint-
                         Gobain Corporation and CertainTeed Corporation (1992-
                         1993)
James F. Harkins, Jr.... Vice President and Treasurer of Saint-Gobain Corporation
                         and CertainTeed Corporation (1995-present); Assistant
                         Treasurer of Saint-Gobain Corporation and CertainTeed
                         Corporation (1992-1995)
James E. Hilyard........ President, Roofing Products Group of CertainTeed
                         Corporation and Vice President of CertainTeed Corporation
                         (1992-present)
Thomas M. Landin........ Vice President of Saint-Gobain Corporation and
                         CertainTeed Corporation (1993-present); Vice President
                         and Director, U.S. Government and Public Affairs of
                         SmithKline Beacham Corporation (1992-1993)
Bradford C. Mattson..... Executive Vice President, Exterior Building Products of
                         CertainTeed Corporation (1996-present); Vice President of
                         Saint-Gobain Corporation (1995-present); President of
                         Vetrotex CertainTeed Corporation (1994-1996); President
                         of Bay Mills Limited (1992-1996); Vice President of
                         CertainTeed Corporation (1992-1996)
John R. Mesher.......... Vice President, General Counsel and Secretary of Saint-
                         Gobain Corporation and CertainTeed Corporation (1997-
                         present); Vice President, Deputy General Counsel and
                         Secretary of Saint-Gobain Corporation and CertainTeed
                         Corporation (1994-1997); Assistant Secretary and
                         Associate General Counsel of Saint-Gobain Corporation and
                         CertainTeed Corporation (1992-1994)

 
                                      S-5

 


                                   PRESENT PRINCIPAL OCCUPATION OR
                                            EMPLOYMENT AND
        NAME                         FIVE-YEAR EMPLOYMENT HISTORY
        ----                       -------------------------------
                   
John P. Mikulak...... President, Vinyl Building Products Group of CertainTeed
                      Corporation and Vice President of CertainTeed Corporation
                      (1992-present)
John J. Sweeney,      Vice President of Saint-Gobain Corporation and
 III................. CertainTeed Corporation (1995-present); Assistant
                      Treasurer of Saint-Gobain Corporation and CertainTeed
                      Corporation (1993-1995); Director of Benefit Investments
                      of Saint-Gobain Corporation and CertainTeed Corporation
                      (1992-1993)
Dorothy C.            Vice President, Communications of Saint-Gobain
 Wackerman........... Corporation and CertainTeed Corporation (1992-present)
Michael J. Walsh..... Vice President, Risk Management of Saint-Gobain
                      Corporation (1995-present); Vice President and Treasurer
                      of Saint-Gobain Corporation (1992-1995); Directeur des
                      Risques et Assurances of Compagnie de Saint-Gobain (1995-
                      present)

 
DIRECTORS AND EXECUTIVE OFFICERS OF BI EXPANSION II CORP.
 
  The following table sets forth the name, present principal occupation and
five-year employment history of the directors and executive officers of BI
Expansion II Corp. All directors and officers listed below are citizens of the
United States except for Mr. Caccini, who is a citizen of Italy and the
business address of each such person is 750 East Swedesford Road, Valley
Forge, Pennsylvania 19482. Directors are indicated by an asterisk.
 


                                      PRESENT PRINCIPAL OCCUPATION OR
                                               EMPLOYMENT AND
          NAME                          FIVE-YEAR EMPLOYMENT HISTORY
          ----                        -------------------------------
                      
George B. Amoss*........ Vice President, Finance of Saint-Gobain Corporation and
                         CertainTeed Corporation (1994-present); Director of
                         CertainTeed Corporation (1997-present); Vice President
                         and Controller of Northern Telecom (1992-1994); Director
                         and Vice President of BI Expansion II Corp. (1997-
                         present)
Gianpaolo Caccini*...... Vice Chairman, President and Chief Executive Officer of
                         Saint-Gobain Corporation (1996-present); Chairman,
                         President and Chief Executive Officer and Director of
                         CertainTeed Corporation (1996-present); Senior Vice
                         President and General Delegate for the United States and
                         Canada of Compagnie de Saint-Gobain (1996-present);
                         President of the Fiber Reinforcements Divisions of
                         Compagnie de Saint-Gobain (1993-1996); President of the
                         Insulation Division of Compagnie de Saint-Gobain (1992-
                         1996); Director of BI Expansion II Corp. (1997-present)
F. Lee Faust............ Vice President, Tax of Saint-Gobain Corporation and
                         CertainTeed Corporation (1993-present); Tax Counsel of
                         Phillips Petroleum (1992-1993); Vice President of BI
                         Expansion II Corp. (1997-present)
James F. Harkins, Jr.... Vice President and Treasurer of Saint-Gobain Corporation
                         and CertainTeed Corporation (1995-present); Assistant
                         Treasurer of Saint-Gobain Corporation and CertainTeed
                         Corporation (1992-1995); Vice President and Treasurer of
                         BI Expansion II Corp. (1997-present)
James E. Hilyard........ President, Roofing Products Group of CertainTeed
                         Corporation and Vice President of CertainTeed Corporation
                         (1992-present); Vice President of BI Expansion II Corp.
                         (1997-present)

 
                                      S-6

 


                                   PRESENT PRINCIPAL OCCUPATION OR
                                            EMPLOYMENT AND
        NAME                         FIVE-YEAR EMPLOYMENT HISTORY
        ----                       -------------------------------
                   
Bradford C.           Executive Vice President, Exterior Building Products of
 Mattson*............ CertainTeed Corporation (1996-present); Vice President of
                      Saint-Gobain Corporation (1995-present); President of
                      Vetrotex CertainTeed Corporation (1994-1996); President
                      of Bay Mills Limited (1992-1996); Vice President of
                      CertainTeed Corporation (1992-1996); Director and
                      President of BI Expansion II Corp. (1997-present)
John R. Mesher....... Vice President, General Counsel and Secretary of Saint-
                      Gobain Corporation and CertainTeed Corporation (1997-
                      present); Vice President, Deputy General Counsel and
                      Secretary of Saint-Gobain Corporation and CertainTeed
                      Corporation (1994-1997); Assistant Secretary and
                      Associate General Counsel of Saint-Gobain Corporation and
                      CertainTeed Corporation (1992-1994); Vice President,
                      Secretary, Clerk and Assistant Treasurer of BI Expansion
                      II Corp. (1997-present)

 
                                      S-7

                                                                 EXHIBIT (a) (2)
 
  Manually signed fax copies of the Letter of Transmittal will be accepted.
The Letter of Transmittal, certificates for Shares and any other required
documents should be sent or delivered by each stockholder of the Company or
such stockholder's broker, dealer, bank, trust company or other nominee to the
Depositary at one of its addresses set forth below.
 
                       The Depositary for the Offer is:
 
                   CHASEMELLON SHAREHOLDER SERVICES, L.L.C.
 
        By Mail:            By Overnight Delivery:            By Hand:
      P.O. Box 3305           85 Challenger Road      120 Broadway, 13th Floor
  South Hackensack, NJ      Mail Drop Reorg. Dept.       New York, NY 10271
          07606            Ridgefield Park, NJ 07660         Attention:
       Attention:                                          Reorganization
     Reorganization                                            Department
        Department
 
                             By Fax Transmission:
                                (201) 329-8936
 
                             Confirm by Telephone:
                                (201) 296-4860
 
  Questions and requests for assistance or for additional copies of this Offer
to Purchase, the Letter of Transmittal and the Notice of Guaranteed Delivery
may be directed to the Information Agent or the Dealer Manager at their
respective telephone numbers and locations listed below. You may also contact
your broker, dealer, bank, trust company or other nominee for assistance
concerning the Offer.
 
                    The Information Agent for the Offer is:
 
                                  GEORGESON 
                                & COMPANY INC.
                                --------------
                               Wall Street Plaza
                           New York, New York 10005
                Banks and Brokers Call Collect: (212) 440-9800
                   All Others Call Toll-Free: (800) 223-2064
 
                     The Dealer Manager for the Offer is:
 
                     MCFARLAND DEWEY SECURITIES CO., L.P.
 
                                230 Park Avenue
                         New York, New York 10169-1450
                                (212) 867-4949