EXHIBIT 99.1

                               CERTIFICATE OF THE
                             CHIEF EXECUTIVE OFFICER
                                   OF ELKCORP

         Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C.ss.
1350):

         I, Thomas D. Karol, Chief Executive Officer of ElkCorp, certify to my
knowledge and belief pursuant to Section 906 of Sarbanes-Oxley Act of 2002 (18
U.S.C.ss. 1350) that:

         (1)      The Annual Report on Form 10-K for the period ended June 30,
                  2002, which this statement accompanies, fully complies with
                  the requirements of section 13(a) or 15(d) of the Securities
                  Exchange Act of 1934; and

         (2)      The information contained in the Annual Report on Form 10-K
                  fairly presents, in all material respects, the financial
                  condition and result of operations of ElkCorp.

Date:  September 26, 2002
                                            By /s/ Thomas D. Karol
                                               ---------------------------------
                                                   Thomas D. Karol
                                                   Chief Executive Officer