Tub Squeaks and Clunks

[jimmyjohn]

My bathtub squeaks and clunks as I move around in it while taking a shower. I've read that this is bad news and can eventually lead to a broken/leaking tub. I've been able to look a bit under the tub at the drain end by removing a drawer cabinet. It looks like there are rigid foam panels under the tub but they don't appear to quite touch the bottom of the tub; maybe 1/4" shy. I've read that there is supposed to be a mortar bed under tubs. I'm wondering if the original builder/owner took a shortcut or something. I've also read that you can stop tub squeak by installing expanding foam under the tub.

Several questions:
1. Is it true that a tub that makes noise is on the verge of failure/leaking?
2. Has anyone ever heard of using rigid foam as tub support?
3. Is expanding foam a practical solution to a squeaking tub problem?
4. If I was to look for professional help to solve this problem would it be a plumber or a construction company...or both?

Thanks for any assistance.

 

[breplum]

What type of tub?
American Standard Americast tubs must NOT have mortar under them.
A good plumber is who I would recommend.

 

[jimmyjohn]

What type of tub?
American Standard Americast tubs must NOT have mortar under them.
A good plumber is who I would recommend.

Thank you for the reply.
I believe the tub is enameled steel.

 

[Twowaxhack]

You could try foam, just don’t overfill it

 

[Bird Doo Head]

Expansion foam is a really good idea, but it's strong stuff while expanding.
Perhaps, if you foam; fill the tub with water & maybe the combined weight will force the foam out sideways instead of up as it expands while curing. (See next paragraph for why...)

A neighbor used expanding foam-in-a-can under a squeaking, clunking steel bathtub with two glitches:
1) It pushed the bath tub up as it cured, snapping wall tiles & pulling the shoe apart.
2) He didn't get it evenly sprayed, so the tub ended up tilted. (I've used spray foam with vinyl tubing as an
extension nozzle to reach way back under stuff.)
3) Safety Eye Protection is very, very important with this stuff. (As is ventilation)

Window & Door spray foam doesn't push, but it might not be strong enough to stop the squeaks.

PLAN B:
Do you have enough access to push lightweight scratch coat plaster under the tub to fill the gaps?
(Something like USG's Structo-Lite or a perlite plaster)
I don't know if this is OK with a steel tub or not. The people here will know.
I used perlite plaster on a fiberglass, deep tub in our home about 35 years ago & it's still good.

Hope This Helps!
Paul

 

[breplum]

On steel tubs, the wood ledger is what is supposed to support, but, we know that is not working in your case.
If you can cut out access from the back wall on the long side, then packing in a masonry mix is likely ideal.
We've only ever used bagged mortar, ideally dryish, but enough water to allow mixing and shaping/shoving.
We use wood in the apron area as a dam to not waste mortar where it is not needed and then 2 x 4 or 6 to be a pushrod.
The Structo-Lite product sounds good...mortar is easy to find...

 

[jimmyjohn]

Thank you, gentlemen, for your useful information and advice.
JJ