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                                                                 Exhibit 3.5







                          CERTIFICATE OF INCORPORATION

                                       OF

                   BUILDING MATERIALS INVESTMENT CORPORATION

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                THE UNDERSIGNED, being a natural person for the purposes of
organizing a corporation under the General Corporation Law of the State of
Delaware, hereby certifies that:

                FIRST: The name of the Corporation is Building Materials
Investment Corporation.

                SECOND: The address of the registered office of the Corporation
in the State of Delaware is 1013 Centre Road, City of Wilmington, County of New
Castle, State of Delaware. The name of the registered agent of the Corporation
in the State of Delaware at such address is The Prentice-Hall Corporation
System, Inc.

                THIRD: The purpose of the Corporation is to engage in any
lawful act or activity for which corporations may be organized under the
General Corporation Law of the State of Delaware, as from time to time amended.

                FOURTH: The total number of shares of capital stock which the
Corporation shall have authority to issue is 1,000, all of which shares shall
be Common Stock having a par value of $.001.

                FIFTH: The name and mailing address of the incorporator is
Shelley A. Sorkin, c/o ISP Management Company, Inc., 1361 Alps Road, Wayne, New
Jersey 07470.

                SIXTH: In furtherance and not in limitation of the powers
conferred by law, subject to any limitations contained elsewhere in these
articles of incorporation, By-laws of the Corporation may be adopted, amended
or repealed by a majority of the board of directors of the Corporation, but any
By-laws adopted by the board of directors may be amended or repealed by the
stockholders entitled to vote thereon. Election of directors need not be by
written ballot.

                SEVENTH: (a) A director of the Corporation shall not be
personally liable either to the Corporation or to any stockholder for monetary
damages for breach of fiduciary duty as a director, except (i) for any breach
of the director's duty of loyalty to the Corporation or its stockholders, or
(ii) for acts or omissions which are not in good faith or which involve
intentional misconduct or knowing violation of the law, or (iii) for any matter
in respect of which such director shall be liable under Section 174 of Title 8
of the General Corporation Law of the State of Delaware or any amendment
thereto or successor provision thereto, or (iv) for any transaction from which
the director shall have derived an improper personal benefit. Neither amendment
nor repeal of this paragraph (a) nor the adoption of any provision of the
Certificate of Incorporation inconsistent with this paragraph (a) shall
eliminate or reduce the effect of this paragraph (a) in respect of any matter
occurring, or any cause of action, suit or claim that, but for this paragraph
(a) of this Article, would accrue or arise, prior to such amendment, repeal or
adoption of an inconsistent provision.



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                (b) The Corporation shall indemnify any person who was or is a
party or is threatened to be made a party to, or testifies in, any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative in nature, by reason of the fact that such
person 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, employee
benefit plan, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by such person in connection with such action, suit or proceeding to
the full extent permitted by law, and the Corporation may adopt By-laws or
enter into agreements with any such person for the purpose of providing for
such indemnification.

                IN WITNESS WHEREOF, the undersigned has duly executed this
Certificate of Incorporation on this 17th day of December, 1998.

                                       /S/ Shelley A. Sorkin
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                                       Shelley A. Sorkin
                                       Sole Incorporator