Can spray foam be used to support a cracked Kohler tub without mortar under it?
Asked by Albino Pinto 
7 months ago
Last Updated: May 21, 2024
So, my Kohler tub has some cracks in it. I have a feeling that when it was put in, they forgot to use mortar underneath. I’ve been considering filling the tub about a third of the way with water and then putting spray foam underneath. I can easily get to the back of the tub. Do you think that the foam would be sturdy enough to support it?
Using windows and door foam to fill it completely will make a big difference. By the way
Before anything else, make sure to inspect the crack repairs
Hey there! As a plumber, I have to say that using foam alone won’t cut it. It’s not the best idea.
Do you have any recommendations other than using foam?
Depends on the location of the leak in the tub. How large is it, and what type of leak is it? Is it just a few drops sporadically or more like a small steady stream?
I believe it’s merely a surface crack right now. Searching for a solution to place beneath the tub for additional support.
Make sure to find where the leak is coming from first. Then dry out the tub and give it a good wipe down. It’s important to have a clean surface before moving on. Head to Home Depot and grab a strong epoxy. Mix it on a plate with ceramwrap to create a composite mixture. Apply it like paint on the tub. Remember not to use the tub for 24 hours after applying the epoxy.
They told me it’s just surface cracks, not a leak.
Sorry, I misunderstood. I thought there was a crack at the bottom of the tub. I missed that it was actually brand new. It was likely just a poor seal job. I’ll make sure to pay closer attention next time.
I think it definitely needs some solid support
I’ve personally used spray foam to level 4″ concrete slabs around my home. While foam may temporarily support the weight, I wouldn’t risk a potential disaster with gallons of water. Plus, it won’t address cracks or leaks.
You can count on the Froth Pack 12 to get the job done. It’s specifically designed for this task and actually outperforms mortar in my experience. Make sure to fill the tub more than 1/3 full.
Yikes, that sounds like a serious issue. Only proper replacement and installation will provide a lasting solution.