Both sources of information may be correct. Some tubs and shower stalls, to save materials cost, are shipped with an integrated foam blocking that matches the shape of the fixture floor and is intended to carry the expected weight of the user.

They are an inferior product; and so the performance will indicate that, especially as you have already experienced. You are probably in for more of the same unless something changes.

But, if this is still under warranty by both the builder and the manufacturer, you need to follow up with them, for a cost-free solution. Determine the product and start with a call to the manufacturer.

Pinoke

Common installation practice is to set fiberglass tubs/pans in drywall compund or like material. This is local "industry standard" and while not a manufacturer's requirement, plaster of paris is mentioned in Lasco's installation instructions.

Thanks for the replies.

Right now, I'm engaged in a debate with the builder about this issue. Lasco's installation instructions for my tub indicate that setting the tub in plaster or mortar is MANDATORY. The builder did not do this, which means that it was an improper installation. However, he isn't willing to fix it, I'm guessing because the only proper fix would be to rip out the entire unit and reinstall it.

I am outside of the builder's standard warranty on the house. However, since the tub wasn't properly installed, I could probably pursue a legal claim against the builder if he isn't willing to budge. However, I'd like to negotiate something without going down that road. I suspect that the cost of legal action would exceed the cost of a new tub, though this isn't the first corner that's been cut, and I'm tempted to at least push this to make a point.

The builder is telling me that if it cracks again in 2, 3, 4 years, he will send someone to fix the cracks again, but of course I do not have that in writing. I am going to see if Lasco will send me a letter regarding the installation procedure, and try to push him with that.

Despite the fact that a new house is a substantial investment by the buyer, if there's one thing I've learned through 2 different custom home builders, it's that even the best builders will only turn out a mediocre product. It's too easy for builders to cut all sorts of corners that you won't notice until later on, and I've had at least one builder threaten to walk away from the table when I wanted to make specific additions to the contract--he stated that it wasn't worth it to him, he would just sell to the next guy in line who would sign the contract without question.

JKG

I think you are right. You needed to pursue this earlier. Probably, your state will not force the builder to comply after 18 months. However, you probably can file a formal complain and have it filed, so that the next complainant has more power to put the builders license at risk.

If you have any desire, you can use that intimidation as leverage to encourage the builder to respond.

If it were me, I would not do a tear-out, unless the damage is severe and the repair is not expected to last. I might consider pumping closed cell poly foam into the floor space and let it spread around the tub.

I have never done this, but I would seek the advice of a spa repair operator. One of their techniques is to inject the foam into a closed cabinet.

Pinoke

Thanks for your comments.

I really do like the builder, but I've found myself repairing or just tearing out and redoing so many things over the past 2 years that, when it came to the tub, I had just about had it. What REALLY irritates me is that no one (builder, wholesaler, factory distributor, etc.) will take ownership or responsibility for the problem. For crying out loud, the guy screwed up the install, just send someone back and try to make it right so that I'm not stuck with a cracked tub again in 2 years (when the warranty on the tub has expired.)

But, houses built 2 years ago aren't generating any revenue for the builder.

JKG

Had the same problem with my plumber 'who said he didn't mortar in tubs anymore' because it wasn't required by the manufacturer.

Then I went to Ferguson- Distributor and had them contact Jacuzzi (my unit was jacuzzi tub) Jacuzzi said to look on its directions on page 14-22 where they currenty say that MORTAR iS REQUIRED for the specific jacuzzi tub I have.

The plumber is trying to take a shortcut & use Liquid nails to glue the feet down on the ubs to the plywood. I am NOT letting them off the hook. If they can't do the install to Jacuzzi specifications, then I don't want them as my plumber. Damn tub cost 5 GRAND. Why can't the plumber READ the DIRECTIONS & FOLLOW THEM ?

solder the stainless steel frame to support the bottom ,and coat a few layer of fibreglass and resin on the bottom of tub back,this way can surely solve the problem .I came across one site that is good ,to see whether it can help you more http://www.mrbaths.com

Here is a link that might be useful: walk in tubs