Dive summary:

• Contractors should expect questions from clients when they submitting claims for higher-than-expected  materials costs.
• Among the inquiries to expect are whether the increased costs were solidly connected to whatever changed on the project and whether there's a good record of the estimated versus the actual costs for that aspect of the work.
• If costs have escalated since materials were ordered, is there anything in the contract about that situation, and have discounts, rebates or other cost-cutters been figured into the claim for more money?

From the article:

There are a variety of increased material costs that may be included in a request for additional compensation or a claim. ...