Tub install queston.

[JT]

Hello. I have learned so much from reading the threads on this site but I have run into a slight problem with a tub install. I have searched and found several topics with the same issue.
I have a Bootz porcelain over steel tub from HD. The tub has a stryofoam base. When the tub rest on it's base it is stable but is no where near level. Bathroom floor is solid concrete and level. When leveled with a stringer the stryofoam base on the srtinger side is about a 1/2" off the ground but does touch on the apron side. This creates lots of flex and squeaks.
Should I just scrape off the stryofoam and motar bed it? When I shimmed it it seems like the stryofoam just compressed around the shims.
Thank you.

[hj]

My personal opinion is that I would NEVER spend time installing a steel tub, unless the customer insisted on it, but that is just my bias. The styrofoam must have been "damaged" because it should set on the floor and support the tub. Low expansion spray foam under the styrofoam should stabilize the tub.

[JT]

The styrofoam looks to be intact and level with the tub with only slight damage to the corner that broke off and where the shims compressed it. It just looks like the styrofoam is not thick enough to make contact with the floor when the tub is level and rest on the stringer and apron. At first I thought the some styrofoam was touching the floor but actually there is a gap under the whole bottom of the tub. The expansion foam sounds like a good idea but I have read that it will gradually compress over time.

[Terry]

Most tubs don't touch the floor.

That's why we use a stringer on the back wall, and shim as needed on the apron.
A steel tub will flex. If you don't want a flexing tub, then going cast iron is nice. Kohler makes really nice cast iron tubs.

I've installed plenty of shower enclosures that had a foam base. It's better than no foam.

[JT]

I thought the tub was supposed to sit on the styrofoam bottom? Or some type of solid base? When I stand in the tub I can see the apron bulge out at least a 1/4".

[Terry]

Hey...........I'm not saying Bootz is a quality tub.

[DBIprop]

I would put a bed of structolite on subfloor and set the tub/styrofoam base into that while still using your stringer for level. Shim outer edge as needed.

[JT]

Terry I agree not a quality tub. It just has so much flex that I think I will go with DBIprop's advice and go with a structolite base. DBIprop do you recommend a barrier of poly between the structolite and styrofoam/tub? And maybe some poly or felt on the concrete subfloor?

[jadnashua]

The bond breaker will mean you could eventually remove the tub without excessive work...it wouldn't hurt.