Our contractor used plywood and foam to support under our tub and it's only been 1 month and it's starting to make a hairline crack about 6 inches long. I called the manufacturer (American Standard) and they told me to look on page 10 in the instruction manual--right there in black & white it says, DO NOT USE FOAM, ONLY use a full mortar bed. I called our contractor immediately and he is coming out next week to look at it. He said on the phone he would squirt in mortar so it "doesn't get worse" but I told him it's a brand new tub and I don't want cracks in it. Cracks in our old tub are the reason for getting the new tub in the first place! He agreed he would put in a new tub.

Hi Bohemana and welcome to the Plumbing pageat at AskMeHelpDesk.com. You piggybacked on an a 6 year old dead thread so I gave you one of your own. In the future, before you post, look in the upper left hand corner for the date.

Our contractor used plywood and foam to support under our tub and it's only been 1 month and it's starting to make a hairline crack about 6 inches long. Your contractor used foam, which consists of mainly air bubbles to bed a tub? BAD IDEA!! when we bed a tub in we puddle cement or mortar to support the tub.

He agreed he would put in a new tub. as well he should and at absolutely no charge to you. He should also bed it well around the drain. Shame on your contractor, he should have known better!
Good luck, Tom

Okay, bad deal. However, you say the contractor has agreed to install a new tub (which he must at his own expense, including all work, sheetrock, mud, paint, tile etc). So what is your question? If you are just looking for clarification, then In my opinion, you should get a new tub with no cost at all for anything, as Tom already said.