Kohler shower base installation question

[Joe88]

Hi everyone,
Had a last minute change of plans to my shower installation and I’m now going to be installing a kohler shower base. Unlike the shower I was previously planning on installing which required a level mortar base for the shower to rest on, this calls for 1” - 5” mounds of mortar under the 4 shower base feet to rest on. If I’m understanding this correctly only 4 points of the shower base will be making contact with the floor which seems like it would cause issues with the base flexing. I’ve only ever installed a tub, so maybe this is common for showers. Can anyone clarify if I’m understanding this clearly? Thanks for your help!

 

[Jadnashua]

What's the base made of? If it's cast iron, it should be fine. Otherwise, would have to evaluate how it was put together and what it was made of.

Too many piles, and it may be harder to level it. Too few piles, and if it can flex, it will. If it is something that can flex, personally, I'd want more piles distributed to support it. IT doesn't need to or really want to be full coverage since then, you'll probably never be able to compress them and support the bottom well, at least evenly.

 

[Sponsor]

 

[Joe88]

What's the base made of? If it's cast iron, it should be fine. Otherwise, would have to evaluate how it was put together and what it was made of.

Too many piles, and it may be harder to level it. Too few piles, and if it can flex, it will. If it is something that can flex, personally, I'd want more piles distributed to support it. IT doesn't need to or really want to be full coverage since then, you'll probably never be able to compress them and support the bottom well, at least evenly.

Thank you for responding. The shower is acrylic, but does seem quite sturdy compared to other acrylic bases I’ve seen. I’m still debating whether to make the mortor mounds just under the 4 feet or add some extra mounds. Seems like a one shot deal, I imagine the mortor will bond the the wood feet well and i probably won’t be able to move it once dry. I think i might give it a test run first and cut some 3/4” plywood and fit under the shower feet. I think that should give me an idea on whether the shower will flex once only those points are supported. Thanks.

 

[Jadnashua]

Some people put a sheet of plastic both on the floor and over the top of the mortar. That does a couple of things:
- helps prevent the subfloor wick too much moisture out of the material, making it weaker
- helps to limit bonding and squeaks.