Your contractor used different materials than the contract

If the contract named a material and something else went in without your agreement, you're generally entitled to what the contract says, or to a credit you accept instead. Find out before more goes on top of it.

A homeowner asked whether it was reasonable to push their builder after finding that a material they shouldn't have used had to be fixed twice in three years. Substitutions happen for ordinary reasons, like a product on back order or a supplier switch. The problem starts when nobody tells the client, and the client finds out when something fails.

What to do

1. Check exactly what the contract or plans named. Brand and model, grade, thickness, rating. "Equal or better" language may allow a substitute, so look for it.
2. Photograph what's installed, including labels and stamps if you can see them.
3. Ask in writing what was used, why, and when you were told.
4. Decide what you want: the named material, or a credit for the difference if the substitute is acceptable. Get whichever it is in writing as a change.
5. If it has failed, look at your warranty and ask for the repair in writing, with photos. See when a contractor won't come back.

For the next job

Name materials in the contract by brand and model, or an allowance with its amount. Ask that any substitution be agreed as a change before it's installed, and check materials when they're delivered, before they're covered up.

When a substitute is fine

Sometimes the substitute really is as good, and pulling it out would waste weeks. You can accept it, but do it on purpose: ask for the product name and spec sheet, check it against what the contract named, and if it's cheaper, ask for the difference back as a credit. Write it down as a change, at a negative price if there's a credit, so the record says you agreed to the substitute and on what terms. That keeps your warranty claim clean if it fails later.

This is general information, not legal advice. States differ on what a home improvement contract and its changes must contain. Check with your state’s contractor licensing board or an attorney.