Offer to Purchase for Cash
                     All Outstanding Shares of Common Stock
         (Including the Associated Rights to Purchase Preferred Stock)

                                       of
                          Brunswick Technologies, Inc.

                                       at

                              $8.00 Net Per Share

                                       by
                           VA Acquisition Corporation

                     an indirect 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 WEDNESDAY, MAY 17, 2000, UNLESS THE OFFER IS EXTENDED.

                                                                  April 20, 2000

To Brokers, Dealers, Commercial Banks,
  Trust Companies and Other Nominees:

   We have been appointed by VA Acquisition Corporation, a Maine corporation
("Purchaser") and an indirect wholly owned subsidiary of CertainTeed
Corporation, a Delaware corporation ("Parent"), which is an indirect wholly
owned subsidiary of Compagnie de Saint-Gobain, a French corporation ("Saint-
Gobain"), to act as Dealer Manager in connection with Purchaser's offer to
purchase all of the outstanding shares of common stock, par value $0.0001 per
share (the "Common Stock"), of Brunswick Technologies, Inc., a Maine
corporation (the "Company"), including the associated rights to purchase
preferred stock (the "Rights" and, collectively with the Common Stock, the
"Shares"), not already beneficially owned by Parent, at a purchase price of
$8.00 per Share, net to the seller in cash, without interest thereon, upon the
terms and subject to the conditions set forth in the Offer to Purchase, dated
April 20, 2000 (the "Offer to Purchase"), and in the related Letter of
Transmittal (which, as amended or supplemented from time to time, together
constitute the "Offer") enclosed herewith. Holders of Shares whose certificates
for such Shares (the "Share Certificates") are not immediately available or who
cannot deliver their Share Certificates and all other required documents to the
Depositary (as defined below) on or prior to the Expiration Date (as defined in
the Offer to Purchase), or who cannot complete the procedure for book-entry
transfer on a timely basis, must tender their Shares according to the
guaranteed delivery procedures set forth in Section 3 of the Offer to Purchase.

   Please furnish copies of the enclosed materials to those of your clients for
whose accounts you hold Shares registered in your name or in the name of your
nominee.

   Enclosed herewith for your information and forwarding to your clients are
copies of the following documents:

   1. The Offer to Purchase, dated April 20, 2000.

   2. The Letter of Transmittal to tender Shares for your use and for the
information of your clients. Facsimile copies of the Letter of Transmittal may
be used to tender Shares.

   3. The Notice of Guaranteed Delivery for Shares to be used to accept the
Offer if Share Certificates are not immediately available or if such
certificates and all other required documents cannot be delivered to


ChaseMellon Shareholder Services, L.L.C. (the "Depositary") on or prior to the
Expiration Date or if the procedure for book-entry transfer cannot be completed
by the Expiration Date.

   4. A printed form of letter which may be sent to your clients for whose
accounts you hold Shares registered in your name or in the name of your
nominee, with space provided for obtaining such clients' instructions with
regard to the Offer.

   5. Guidelines for Certification of Taxpayer Identification Number on
Substitute Form W-9.

   6. A return envelope addressed to ChaseMellon Shareholder Services, L.L.C.,
as Depositary.

   Your prompt action is requested. We urge you to contact your clients as
promptly as possible. Please note that the Offer and withdrawal rights expire
at 12:00 midnight, New York City time, on Wednesday, May 17, 2000, unless the
Offer is extended.

   The Offer is conditioned upon, among other things: (a) there being validly
tendered and not properly withdrawn prior to the Expiration Date a number of
Shares that, when added to the Shares currently owned by an affiliate of
Parent, represents at least a majority of the outstanding Shares on a fully
diluted basis (including the exercise of all outstanding options) as of the
date the Shares are accepted for payment pursuant to the Offer; (b) the Rights
having been redeemed by the Board of Directors of the Company, or Purchaser,
Parent and Saint-Gobain being satisfied, in their sole discretion, that such
Rights are inapplicable to the Offer and any subsequent business transaction
involving Purchaser, Parent, Saint-Gobain and the Company, including a merger
or similar business combination (the "Merger") between the Company and
Purchaser, pursuant to which each then outstanding Share (other than Shares
held by the Company in treasury, or beneficially owned by Purchaser, Parent,
Saint-Gobain or any other direct or indirect wholly owned subsidiary of
Purchaser, Parent or Saint-Gobain, or Shares, if any, that are held by
shareholders who are entitled to and who properly exercise dissenters' rights
under Maine law) would be converted pursuant to the terms of the Merger into
the right to receive an amount in cash equal to the per Share price paid
pursuant to the Offer, without interest, upon surrender of the Share
Certificate representing such Share, less any required withholding tax; (c)
Purchaser, Parent and Saint-Gobain being satisfied, in their sole discretion,
that the provisions of Section 611-A of the Maine Business Corporation Act
("MBCA") are inapplicable to the acquisition of Shares pursuant to the Offer
and any subsequent business transaction involving Purchaser, Parent, Saint-
Gobain and the Company, including the Merger; and (d) any applicable waiting
period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as
amended, and the regulations thereunder having expired or been terminated (or,
to the extent required, governmental approvals obtained).

   In order to take advantage of the Offer, (1) a duly executed and properly
completed Letter of Transmittal (or a facsimile thereof) and any required
signature guarantees, or an Agent's Message (as defined in the Offer to
Purchase) in connection with a book-entry delivery of Shares, and other
required documents should be sent to the Depositary, and (2) either Share
Certificates representing the tendered Shares should be delivered to the
Depositary or such Shares should be tendered by book-entry transfer and a Book-
Entry Confirmation (as defined in the Offer to Purchase) with respect to such
Shares should be delivered to the Depositary, all in accordance with the
instructions set forth in the Letter of Transmittal and the Offer to Purchase.

   Holders of Shares whose Share Certificates are not immediately available or
who cannot deliver their Share Certificates and all other required documents to
the Depositary on or prior the Expiration Date, or who cannot complete the
procedure for delivery by book-entry transfer on a timely basis, must tender
their Shares according to the guaranteed delivery procedures set forth in
Section 3 of the Offer to Purchase.

   Purchaser will not pay any commissions or fees to any broker, dealer or
other person (other than the Dealer Manager, the Depositary and InnisFree M&A
Incorporated (the "Information Agent") (as described in the Offer to Purchase))
for soliciting tenders of Shares pursuant to the Offer. Purchaser will,
however, upon request, reimburse you for customary clerical and mailing
expenses incurred by you in forwarding any of the enclosed materials to your
clients. Purchaser will pay or cause to be paid any stock transfer taxes
payable on the transfer of Shares to it, except as otherwise provided in
Instruction 6 of the Letter of Transmittal.

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   Inquiries you may have with respect to the Offer should be addressed to the
Information Agent or the undersigned, at the respective addresses and telephone
numbers set forth on the back cover of the Offer to Purchase. Additional copies
of the enclosed materials may be obtained from the Information Agent.

                                          Very truly yours,

                                          Lehman Brothers

   NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU
OR ANY OTHER PERSON THE AGENT OF PURCHASER, PARENT, SAINT-GOBAIN, THE DEALER
MANAGER, THE DEPOSITARY OR THE INFORMATION AGENT, OR ANY AFFILIATE OF ANY OF
THEM, OR AUTHORIZE YOU OR ANY OTHER PERSON TO MAKE ANY STATEMENT OR USE ANY
DOCUMENT ON BEHALF OF ANY OF THEM IN CONNECTION WITH THE OFFER OTHER THAN THE
ENCLOSED DOCUMENTS AND THE STATEMENTS CONTAINED THEREIN.

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