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.
Section 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. Section 1350) that:

         (1)      The Quarterly Report on Form 10-Q for the period ended
                  September 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 Quarterly Report on Form 10-Q
                  fairly presents, in all material respects, the financial
                  condition and results of operations of ElkCorp.

Date: November 13, 2002
                                            By /s/ Thomas D. Karol
                                               -----------------------
                                               Thomas D. Karol
                                               Chief Executive Officer