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                                                                   EXHIBIT 10.5

                         WAIVER/AMENDMENT NUMBER THREE
                                 TO CALMAT CO.
                                CREDIT AGREEMENT
                          DATED AS OF AUGUST 20, 1991

         This Waiver to the Credit Agreement described below is entered into as
of February 5, 1993.

         1.      Preliminary Statement.  Reference is made to a Credit
Agreement dated as of August 20, 1991 (which, as it may be amended, extended or
supplemented from time to time, is herein called the "Credit Agreement") among
CalMat Co. (the "Borrower"), the lenders which are a party thereto (the
"Lenders") and The First National Bank of Chicago, as agent for the Lenders
(the "Agent").  Section 6.18 of the Credit Agreement requires the Borrower to
meet a minimum fixed charge coverage ratio at the end of each fiscal quarter
for the four-quarter period then ended.  The Borrower has informed the Agent
that it is in violation of Section 6.18 for the period ending December 31, 1992
and has requested that this violation be waived.

         2.      Waiver.  The Required Lenders hereby waive until March 31,
1993 any violation  of Section 6.18 of the Credit Agreement for the
four-quarter period ended December 31, 1992.  On and after March 31, 1993 the
Borrower shall be required to be in compliance with Section 6.18 as written
without giving effect to this Waiver, including, without limitation, compliance
with the minimum fixed charge ratio required under section 6.18 for the
four-quarter period ending March 31, 1993.

         3.      Definitions.  Unless the context shall otherwise require, all
terms used herein which are defined in the Credit Agreement shall have the
meanings assigned to them therein.

         4.      Expenses.  The Borrower shall pay all expenses of the Agent
(including reasonable charges for in-house counsel) incurred by the Agent in
the preparation of this Amendment.

         5.      Reference to and Effect on the Loan Documents.  Upon the
effectiveness hereof, each reference in the Credit Agreement and the other Loan
Documents to "this Credit Agreement", "hereunder", "hereof", "herein" or words
of like import referring to the Credit Agreement, and each reference in the
Notes and the other Loan Documents to the "Agreement", "thereunder", "thereof",
or words of like import referring to the Agreement, shall mean and be a
reference to the Credit Agreement, as modified hereby.  Except as expressly
waived hereby, all of the representations, warranties, provisions, covenants,
terms and conditions of the Credit Agreement shall remain unaltered and in full
force and effect.

                                  THE FIRST NATIONAL BANK OF CHICAGO
                                        Individually and as Agent
                                  By:        /s/ Gene Benke
                                     ------------------------------------------
                                        Its:  Senior Vice President
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