EXHIBIT 99.2 CERTIFICATE OF THE CHIEF FINANCIAL OFFICER OF ELKCORP Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350): I, Harold R. Beattie, Jr., Chief Financial 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. Dated: November 13, 2002 By /s/ Harold R. Beattie, Jr. -------------------------- Harold R. Beattie, Jr. Chief Financial Officer