EXHIBIT 99.2

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

The undersigned hereby certifies, in her capacity as Chief Financial Officer of
Modtech Holdings, Inc. (the "Company"), for purposes of 18 U.S.C. Section 1350,
as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that based
on her knowledge:

     .    the Quarterly Report of the Company on Form 10-Q for the period ended
          June 30, 2002 (the "Report") fully complies with the requirements of
          Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934;
          and

     .    the information contained in the Report fairly presents, in all
          material respects, the financial condition and results of operations
          of the Company.

Dated:  August 14, 2002

                                                 /s/ Shari L. Walgren
                                                 -------------------------------
                                                 Shari L. Walgren
                                                 Chief Financial Officer

This certification accompanies this 10-Q Report pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002 and shall not be deemed filed by the Company for the
purposes of Section 18 of the Securities Exchange Act of 1934, as amended.