When an item or class of materials is specified exclusively by trade name, manufacturer's name or by catalog reference, may the Contractor substitute another kind of material?

Generally, only such specified item shall be used for completing the Work as required by the Contract.


However, the Contractor may substitute another material, article or process if the substitution is approved in writing by the Owner. The Contractor shall be responsible for the materials and articles installed or used  without the Owner’s approval.


Samples of materials for use in reinforced concrete work such as steel bars, cement, and aggregates and their certificates of origin shall be approved by the Owner.


The Owner’s action on the request for substitution of materials  or for approval of samples of materials shall be given in a timely manner.