Home>Discussions>BATHROOMS>Heated floor under a shower, is that legal/safe?
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Seth
Heated floor under a shower, is that legal/safe?
Seth

At my fiancee's insistence we are installing heated floors in the master bath, but I don't know if I should be ordering enough to install them under the shower as well. Is that legal or safe? The electrician is doing the connections, we may do the tiling or may hire it out.

Also, is buying heating systems as a mat worth the $100+ premium vs. buying a large roll of wire with some tie downs? We re doing 100-105 sqft if no shower, 110-120 with shower.

The math is a little fuzzy because 1) we haven't nailed down the size of the shower and 2) three walls have Mansard ceilings so you can't actually stand next to the edge of the wall, so I figure why heat where you can't stand and I will stop the heat 16" before the wall. I'm also not sure if I should heat where we would like some custom cabinets built (to fit with the sloping ceiling) but I suspect it will be a long time before we can get such cabinets. I'm also not heating under the vanity.

MLB Construction
Re: Heated floor under a shower, is that legal/safe?
MLB Construction

i've installed a heated floor in a shower multiple times. this can be done. below the copper pan and on top of the subfloor you put the mat with a 1/4 layer of floor leveler or thinset on it. then your copper pan and install the floor as you normally would. i told customers it might take a little longer for the shower floor to warm up as opposed to a regular tile floor but they have all said it heated up quicker than i said it would.

ed21
Re: Heated floor under a shower, is that legal/safe?
ed21

It sounds nice to have a heated shower floor.
I wouldn't worry about full coverage where you can't stand, but it wouldn't hurt if you do. The cost of a few extra sq.ft. is minimal compared to the the entire job.
I would not install it under where cabinets will be placed.

Seth
Re: Heated floor under a shower, is that legal/safe?
Seth

Thanks to both of you!

I was going to install cement board over the subfloor like I did in another home, but this subfloor is random 150-year-old pine boards. So my next thought was a plywood subfloor and then cement board, but I hear rumor of a product which is the two of those combined. Have either of you used such a thing? How hard is it to work with?

HoustonRemodeler
Re: Heated floor under a shower, is that legal/safe?
HoustonRemodeler

You'll have a number of issues to deal with including deflection of the floor joists, waterproofing, and getting the heating past the curb.

You'll fare well by taking a few pictures and starting a thread on the John Bridge Tile Forum.

FWIW Boston is famous for its copper pans. While they are an accepted waterproofing method, they are not required or the norm in other parts of the country. CA is the land of hot mop. Austin is known for fiberglass.

dj1
Re: Heated floor under a shower, is that legal/safe?
dj1

If your floor is tile or stone, there is no issue with heat under the floor, assuming of course that the sub floor and joists deflection can accommodate the tiles/stone.

Seth
Re: Heated floor under a shower, is that legal/safe?
Seth

I will be putting in 3/4 plywood and cement board. I completely forgot I also need to build a shower stall, a curb, maybe a bench, and if I do a bench maybe I should heat that too...

Mastercarpentry
Re: Heated floor under a shower, is that legal/safe?
Mastercarpentry

Nothing wrong with having warm buns to go with the toasty toes!

Phil

Seth
Re: Heated floor under a shower, is that legal/safe?
Seth

So I just found the instructions ****** for the mat I was considering and it says to not install it under a shower. So confused...

ed21
Re: Heated floor under a shower, is that legal/safe?
ed21

I have to say I was a little surprised to hear that electric heat was being installed is a shower, but assumed you knew it could be done.
If the manufacturer says not to do it, I wouldn't.
I still think a warm floor and seat sounds nice.
A quick on-line search came up with a company that has a shower safe mat.
http://www.suntouch.com

Lynne
Re: Heated floor under a shower, is that legal/safe?
Lynne

Doesn't warm up nicely after the hot water's been on a few minutes?

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