I have an acrylic shower/tub. The floor flexes. What product can be injected underneath to provide support.

Question

I have an acrylic, one piece shower/tub. The floor of the tub is "soft" in one area - ie, it has flex and is apparently not properly supported. I am concerned that, over time, we will crack the fiberglass because of the flexing.

I have spoken to a bathtub repair firm which says there is some kind of spray in foam which hardens to a cement-like hardness and can be injected in underneath the tub to provide proper support but they have not indicated what this is. Can you please advise what products can be used and refer me to any sites which discuss and sell such products ?

thanks

I am aware of the foams but am not sure if they are the same thing the bathtub repair folks were speaking of. I have to believe the latex foam is definitely not since it would have to support people of 200+ lbs. The other foam mentioned I am not aware of. I'm not sure why that foam would cause so much force that it would buckle the tub - wouldn't it simply expand into (or our of) the cavity created to inject the foam (like the hole in the wall I'll need to create ?

The product used by the installers supposedly hardens to something cement-like but I am not clear on how much it expands.

Answer 1

Sensible is correct - it should have been bedded in mortar. Your best bet would be to look for a way to get mortar under the tub - from underneath or an adjacent room. It may entail a little drywall repair, but that's normally pretty minor. And if you do find a way to get mortar in there, make it's just plain old mortar that doesn't expand.

Injecting urethane foam might help a little, but I would not count on it for a permanent fix.

I've heard of this problem more than once over the years. There *are* mortar guns (sorta like caulking guns for mortar). I haven't seen one used for this application, but I think that it would have a chance of working. A brick mason might have one.

Answer 2

Aerosols of expanding foam are available and are made just for this purpose, a small hole is drilled on the outside of the base to take the application tube and the foam is injected, it will expand to about 7 to 10 times it's volume and reaches all the cavity corners and dries rigid, a good idea when buying this is to get a can of the special cleaner that is made for cleaning up as no other cleaner is suitable.The foam is not expensive but there is a use by date on the can, so check this when buying, these should be available at most large DIY stores.

Answer 3

The foam from a can will fill in the space, but will not be ridgid enough to accomplish what you want. The tub should have had a mortarbed installed when it was set. The high expansion foam could also push the bottom of the tub upwards in a weak spot and break it. Not likely, but "could" happen.

Answer 4

DANGER Will Robinson! Be very careful with expanding foam. There are two types commonly sold at most home stores. They are both made by the same company and they both work well. One is "Latex" based and the other...well its not. The latex based foam was designed to go around windows and doors. The other was made to fill in cracks in masonry and walls. Latex is white and expands about 3 times its size. The other "yellow" expands to about 10 to 15 times its size. The latex will clean up with water before it set completely. The yellow can only be cleaned using paint thinner of acetone. The "yellow" foam will expands so greatly that it will cause your tube floor to buckle and bow upward.

Answer 5

you might want to go to either Lowes or Home Depot and ask someone in the plumbing dept if the canned foam will work for this. It is an open cell foam and does get somewhat rigid. might work for your problem without having to take the shower out.

Answer 6

It would depend on where you live. There a Avon store popping up everywhere. And to find you local rep. I am sure you can acess that through the internet. Or the 800 number. Hope that this helps.