Different manufacturers have different requirements. Some prohibit it, some allow them with no restrictions, some only allow them if they are under a waterproof membrane.

In my house, I have whole house hydronic RFH, even under the shower. For all practical purposes, I really don't think you'd notice much of a difference between having the RFH under your shower tiles and having the shower water warm your floor tiles before you step in the shower.

But if you do want to do it, there are ways to do it.

I think ours is Laticrete brand. Our shower is curbless and the radiant floor heat covers wet and dry areas. I had already perused the John Bridge tile forum where they talk a lot about radiant floor heat so I knew I could have it under the wet area as well. My contractor did ask me initially so this probably helped him decide which product to use.

And we LOVE the open shower concept. No door to mess with. Adds a lot to the relaxation of a shower.

This post was edited by elphaba on Mon, May 27, 13 at 23:34

My GC wants $2,000 to put hydronic RH in the walls of a corner shower with 2 exterior walls in a 5x7 space. We are in Maine building a new house for aging in place. I am wondering if we should pay up for the RH or install a shower door for about 1K. Any opinions on that?