<PAGE>   1
                                                                  EXHIBIT 10.17

                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT

         AMENDMENT NO. 2, dated as of March 8, 2001 (this "Amendment"), to the
Amended and Restated Credit Agreement, dated as of December 4, 2000, among
Building Materials Corporation of America (the "Borrower"), the lenders from
time to time party thereto, Fleet National Bank, as Documentation Agent, Bear
Stearns Corporate Lending Inc., as Syndication Agent, and The Bank of New
York, as Swing Line Lender and as Administrative Agent (in such capacity, the
"Administrative Agent") (as amended to the date hereof, the "Credit
Agreement").

                                   RECITALS

         I.       Capitalized terms used herein which are not otherwise
defined herein shall have the respective meanings ascribed thereto in the
Credit Agreement.

         II.      The Borrower has requested that the Administrative Agent and
the Lenders amend the Credit Agreement upon the terms and conditions contained
in this Amendment, and the Administrative Agent and the Required Lenders are
willing so to do.


         Accordingly, in consideration of the Recitals and the covenants and
conditions hereinafter set forth, and of other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged, the
parties hereto hereby agree as follows:

         1.       Effective as of December 4, 2000, Schedule 8.5 to the Credit
Agreement is amended and restated in its entirety in the form of Schedule 8.5
attached hereto.

         2.       Paragraph 1 shall not be effective until the Administrative
Agent shall have received this Amendment, duly executed by a duly authorized
officer or officers of the Borrower, the Guarantors, the Administrative Agent
and the Required Lenders.

         3.       On the date hereof, each Credit Party hereby (a) reaffirms
and admits the validity and enforceability of each Loan Document (as amended
by this Amendment) to which it is a party and all of its obligations
thereunder, (b) agrees and admits that it has no defenses to or offsets
against any such obligation, and (c) represents and warrants that no Default
or Event of Default under any Loan Document (as amended by this Amendment) has
occurred and is continuing, and that each of the representations and
warranties made by it in the Loan Documents (as amended by this Amendment) to
which it is a party is true and correct in all material respects with the same
effect as though each such representation and warranty had been made on the
date hereof, except to the extent such representation and warranty
specifically relates to an earlier date, in which case such representation and
warranty shall have been true and correct on and as of such earlier date.

         4.       In all other respects, the Loan Documents shall remain in
full force and effect, and no consent or amendment in respect of any term or
condition of any Loan Document contained


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herein shall be deemed to be a consent or amendment in respect of any other
term or condition contained in any Loan Document.

         5.       This Amendment may be executed in any number of counterparts
all of which, taken together, shall constitute one agreement. In making proof
of this Amendment, it shall only be necessary to produce the counterpart
executed and delivered by the party to be charged. All future references to
the Credit Agreement shall mean and refer to the Credit Agreement as amended
hereby.

         6.       THIS AMENDMENT IS BEING EXECUTED AND DELIVERED IN, AND IS
INTENDED TO BE PERFORMED IN, THE STATE OF NEW YORK AND SHALL BE CONSTRUED AND
ENFORCEABLE IN ACCORDANCE WITH, AND BE GOVERNED BY, THE INTERNAL LAWS OF THE
STATE OF NEW YORK, WITHOUT REGARD TO PRINCIPLES OF CONFLICT OF LAWS, BUT
INCLUDING SECTION 5-1401 OF THE GENERAL OBLIGATIONS LAW.

                           [signature pages follow]


                                      2

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                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA


         AS EVIDENCE of the agreement by the parties hereto to the terms and
conditions herein contained, each such party has caused this Amendment No. 2
to be executed on its behalf.


                               BUILDING MATERIALS CORPORATION OF AMERICA


                               By: /s/ Susan B. Yoss
                                  -----------------------------------------
                               Name: Susan B. Yoss
                                    ---------------------------------------
                               Title: Senior Vice President and Treasurer
                                     --------------------------------------




<PAGE>   4


                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA


                               THE BANK OF NEW YORK, as Swing Line Lender, as
                               an Issuing Bank, as Administrative Agent and as
                               a Lender


                               By:  /s/ David C. Judge
                                   -----------------------------------
                               Name: David C. Judge
                                    ----------------------------------
                               Title: Senior Vice President
                                     ---------------------------------


<PAGE>   5

                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA

                               FLEET NATIONAL BANK


                               By:  /s/ Peggy Peckham
                                   -----------------------------------
                               Name: Peggy Peckham
                                    ----------------------------------
                               Title: Senior Vice President
                                     ---------------------------------


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                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA

                               BEAR STEARNS CORPORATE LENDING INC.


                               By:  /s/ Victor T. Bulzaccehellci
                                   -----------------------------------
                               Name: Victor T. Bulzaccehellci
                                    ----------------------------------
                               Title: Managing Director
                                     ---------------------------------


<PAGE>   7

                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA

                               THE CHASE MANHATTAN BANK, as an Issuing Bank
                               and as a Lender


                               By:    /s/ Peter A. Dedousis
                                   -----------------------------------
                               Name:  Peter A. Dedousis
                                    ----------------------------------
                               Title: Managing Director
                                     ---------------------------------


<PAGE>   8

                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA

                               THE BANK OF NOVA SCOTIA


                               By:  /s/ Daniel A. Costigan
                                   -----------------------------------
                               Name: Daniel A. Costigan
                                    ----------------------------------
                               Title: Director
                                     ---------------------------------


<PAGE>   9

                               AMENDMENT NO. 2
                                      TO
                    AMENDED AND RESTATED CREDIT AGREEMENT
                  BUILDING MATERIALS CORPORATION OF AMERICA

AGREED AND CONSENTED TO:


BMCA INSULATION PRODUCTS INC.
BUILDING MATERIALS INVESTMENT CORPORATION
BUILDING MATERIALS MANUFACTURING CORPORATION
DUCTWORK MANUFACTURING CORPORATION
GAF LEATHERBACK CORP.
GAF MATERIALS CORPORATION (CANADA)
GAF PREMIUM PRODUCTS INC.
GAFTECH CORPORATION
LL BUILDING PRODUCTS INC.
WIND GAP REAL PROPERTY ACQUISITION
    CORP.


By:  /s/ Susan B. Yoss
    ----------------------------------------
Name:  Susan B. Yoss
      --------------------------------------
Title:  Senior Vice President and Treasurer
       -------------------------------------