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                                                                    Exhibit 3.17



                          CERTIFICATE OF INCORPORATION

                                       OF

                               GAFTECH CORPORATION

                                   * * * * * *

                  1. The name of the corporation is

                               GAFTECH CORPORATION


                  2. The address of its registered office in the State of
Delaware is The Prentice-Hall Corporation System, Inc., 229 South State Street
in the City of Dover, County of Kent. The name of its registered agent at such
address is The Prentice-Hall Corporation System, Inc.

                  3. The nature of the business and the purposes of the
Corporation to be conducted or promoted are:

                        a. To engage in the purchase, sale and licensing of
technology, in particular technology related to roofing, construction generally
and glass fiber, and related sales of equipment and performance of services
relating to the manufacture, installation, maintenance and use of roofing
products and glass fiber.

                        b. To engage in any lawful act or activity for which
corporations may be organized under the General Corporation Law of Delaware.

                        c. To conduct its business in any of the states,
territories, colonies or dependencies of the United States, and in any and all
foreign countries; to have one or more offices therein, and to hold, purchase
and convey real and personal property, both within and without limit as to
amount.




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                        d. Without in any manner limiting any of the objects and
powers of the Corporation, but in furtherance thereof, it is hereby expressly
declared and provided that the Corporation shall have power to acquire and
undertake the goodwill, property, rights, franchises and assets of every kind,
and the liabilities, of any person, firm association or corporation, in whole or
in part, and pay for the same in cash, stock or bonds of the Corporation or
otherwise; no enter into, make, perform and carry out contracts of every kind
and for any lawful purpose; to make and issue its bond, debentures, promissory
notes and other negotiable instruments, and to pledge any stock, bonds or
obligation, or mortgage any property which may be acquired by it to secure the
same, to guarantee any dividends, bonds, contracts or other obligations; to
purchase, hold and reissue the shares of its capital stock, and to do any or all
other things to the same extent as natural persons might or could do, and in any
part of the world.

                  4. The total number of shares of stock which the Corporation
shall have the authority to issue is:

                        a. One Thousand (1,000) shares of Common Stock, par
value $2.00 per share. No holder of Common Stock shall have any preemptive right
of subscription to any share of any class of stock or other securities of the
Corporation, whether now or hereafter authorized or issued. Holders of such
shares shall be entitled to one vote per share on all matters upon which
stockholders are entitled to vote.

                        b. One Thousand (1,000) shares of Preferred Stock, no
par value. No holder of Preferred Stock shall have any preemptive right of
subscription to any share of any class of stock or other securities of the
Corporation, whether now or hereafter authorized or issued. The Preferred Stock,
no par value, may be issued in one or more series, from time to time, with such


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designations, preferences and relative participating, option or other special
rights and qualifications, limitations or restrictions thereon as may be
provided in a resolution or resolutions adopted by the Board of Directors of the
Corporation. The authority of the Board of Directors of the Corporation
includes, but is not limited to, the determination or fixing of the following
with respect to the shares of each series of such Preferred Stock, no par value,
viz., (i) the number and designation of shares; (ii) the dividend rate and
whether the dividends are to be cumulative; (iii) whether shares are to be
redeemable and, if so, the terms and provisions applying thereto; (iv) whether
there shall be a sinking fund and, if so, the terms and provisions applying
thereto; (v) whether the shares should be convertible and, if so, the terms and
provisions applying thereto; (vi) rights on liquidation; (vii) what, if any,
restrictions on the payment of dividends on other classes of stock shall apply;
(viii) what voting rights are to apply; and (ix) any other rights, preferences
and limitations. The Corporation may from time to time issue and dispose of any
of the authorized and unissued shares of Preferred Stock, no par value, for such
consideration as may be fixed from time to time by the Board of Directors
without action by the stockholders.

                  5. The name and mailing address of the incorporator is as
follows:

NAME                        MAILING ADDRESS
- ----                        ---------------

Isabelle J. Lorans          GAF Corporation
                            1361 Alps Road
                            Wayne, New Jersey  07470

                  6. The corporation is to have perpetual existence.



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                  7. In furtherance and not in limitation of the powers
conferred by statute, the Board of Directors is expressly authorized to make,
alter or repeal the Bylaws of the Corporation.

                  8. Elections of Directors need not be by written ballot unless
the Bylaws of the Corporation shall so provide. Meetings of stockholders may be
held within or without the State of Delaware, as the Bylaws may provide. The
books of the Corporation may be kept (subject to any provision contained in the
statutes) outside the State of Delaware at such place or places as may be
designated from time to time by the Board of Directors or in the Bylaws of the
Corporation.

                  9. The Corporation shall, to the full extent permitted by
Section 145 of the General Corporation Law of the State of Delaware, as amended
from time to time, indemnify all persons whom it may indemnify pursuant thereto.
The indemnification herein provided for shall not be deemed exclusive of any
other rights to which those indemnified may be entitled under any Bylaw,
agreement, note of stockholders or disinterested directors or otherwise, both as
to action in his official capacity and as to action in another capacity while
holding such office, and shall continue as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of the
heirs, executors and administrators of such person.

                  The Corporation shall have power to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the Corporation, or is or was serving at the request of the Corporation
as a director, officer, employee or agent of another corporation, partnership,
joint venture, trust or other enterprise against any liability asserted against
him and incurred by him in any such capacity, or arising out of his status as
such, whether or not the Corporation would have the power to indemnify him


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against such liability under the provisions of Section 145 of the General
Corporation Law of the State of Delaware.

                  10. To the fullest extent permitted by Section 102(b)(7) of
the General Corporation Law of the State of Delaware, as amended from time to
time, a director of this Corporation shall not be liable to the Corporation or
its stockholders for monetary damages for breach of fiduciary duty as a
director.

                  11. The Corporation reserves the right to amend, alter, change
or repeal any provision contained in this certificate of Incorporation, in the
manner now or hereafter prescribed by statute, and all rights conferred upon
stockholders herein are granted subject to this reservation.


Signed June 17, 1987                         /s/ ISABELLE J. LORANS
                                        -------------------------------
                                                 Isabelle J. Lorans






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