Light load bearing foam
I had remodeled our first floor master bath and installed a new shower base and walls. I did glue down the base posts but something has become loose and there is movement in floor and lots of squeaks when moving around base. I hate to tear out new walls to re-install base.
I have access to under floor from Basement and have cut some holes to access and tried putting in spacers to support base but it seems to have made it worse. I would like to know if there is a spray foam spray that would handle the weight of a person and base and not allow movement downward that causes the squeaks. I would close up the openings I made and there is still access under base with the opening made in floor for the drain. Frustrated an hoping someone has an easy fix for this. Thank you
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Hi Rstagl.
I have never done this myself, but I have heard of people injecting canned spray foam beneath squeaky tubs to stiffen them up. First, I would make sure that it is the shower base that is flexing and squeaking and not the framing and subfloor, though.
I would imagine that the foam you choose (a low-expansion foam vs. a highly expanding big gap filler) would depend on how how much space there is to fill, and the ease of access.
This is going to make it a bit more difficult to pull the base when remodeling because polyurethane foam is a strong adhesive, but you generally have the recip saw out for that work anyway.
I bet some other GBA members will have some thoughts on this and maybe some techniques to share.
Many shower and tub manufacturers recommend foam used this way. I would first check the installation instructions and see if they have a recommendation.
Be careful. I've had a tub lift when I used too much foam underneath. Trying to compensate by standing in it did nothing.
Maybe it would be possible to fill the tub with water while injecting the foam? The tub will Wright a LOT more full of water, and hopefully have less chance of lifting due to foam expansion.
Bill
I'll second Malcolm's warning, because I've had the same thing happen. With low-expansion foam and a light touch you should be ok. Mortar used to be the recommended filler, and some manufacturers still recommend it. Hard to get it into place after installation, though.
Thanks for the update. I was leaning on spraying closed cell expansion foam. I do have room to spread it around and I especially appreciate the warning on using low expansion foam and avoid it lifting base. Didnt even consider that being a problem, figured it would come out by drain area as that opening is pretty large, around 7- 8" Dia
Could anyone suggest a foam brand best for this kind of application? least compression over time
Again , Thanks guys, I'm new to this forum.
Canned foam should work well. Use less than you imagine is needed. I had great success for years setting whirlpools and tub or shower bases down into a full bucket or box of all purpose taping mud. Put a piece of poly on top of mud if you are concerned about it adhering to the base.