Radiant floor heat

[jphavener]

Okay, I want to install radiant floor heat in my master bath(new construction, concrete slab). I'm trying to convince myself that it won't be that difficult but I'm not so sure. My concern is getting the tiles flat. How in the heck do you get that heating mat laid down and get the tiles to lay flat on top of it? The instructions simply say to put the mat down with the double sided tape or hot glue, then lay the tile over it. Sounds too easy to me. Anybody have experience with this?

[MarcusEngley]

Hi JP -- got a first name?

Do a search on "floor heat" -- you'll get tons of info. Also, try the "Liberry", as there's a bunch of archived info there as well. I'll get you started:

Heat

More heat

Still more!

That should give you some confidence to start off with -- any more questions, heat related or otherwise, keep them in this thread, so everyone can keep track of what's going on...

Welcome!
Marcus

[jphavener]

Thanks Marcus! The name is Jeff. I usually sign my posts, just forgot this time. I'll check those links out and post up more questions if I have them!

[Blayne]

Jeff-

The heated flooring systems are generally very thin. So once you staple it to the floor, the thinset for your tiles ends up being thicker than the heated flooring wires.

I haven't installed mine yet, but I have received it. Once you see the stuff first-hand I think you'll understand how it will fit. I'll be installing in my shower area in the next week or so, and then a little later throughout the rest of the bathroom.

Which brand are you going with? I've actually got two different ones, Thermosoft for this Master bathroom/shower project and then WarmZone ComfortTouch for a guest bathroom. The ThermoSoft heated wire is in an open-mesh mat, but it can be cut to fit areas. The WarmZone stuff is just a wire, and you fasten it down with supplied clips.

-Blayne

[jphavener]

Blayne,

I'm using the Suntouch mats. I have a friend who used it also and he likes it. Guess I should ask him how he did it.

I've got the product here in my grubby little paws and I guess I should have asked whether or not to back butter the tiles or trowel the thinset over the mat. I read a post that got into using SLC and Ditra and all of that and that sounds like entirely too much effort on my part. I already have about 3 weeks of work on my plate as it is.

Jeff

[flatfloor]

The SLC is an alternate to thinset some find it easier to just pour over the mat rather than troweling the thinset on.

Ditra is an insurance policy to offset any possible expansion and contraction.

[PatM]

I have put down Suntouch mats in both my kitchen and dining room under 12 x 12 x 3/8 porcelin tile. They went down very smooth and there was no difference in the tile over the mats. The problem is the wiring that must run across the under the floor. I used a router and cut a shallow groove and that worked fine. Hope you enjoy, they are great in winter and haven't noticed any change in the electric bill.

Pat

[jphavener]

Thanks for the info Pat. I'm gonna have to use a grinder since I'm on a slab but I was planning on making a trough for the wires. One question for you, did you just put down the mats then trowel the thinset on top of the mat? If so did you have any problems snagging the mat with the notched trowel?

Flatfloor, it was my understanding that the SLC was used to "embed" the mat then after that dried the tile was set using thinset on top of the dried SLC. Is this incorrect? The way you explained it makes it sound as if they are setting the tile in the SLC. I think that you mean they are using the SLC instead of troweling thinset on to create a flat surface. Using thinset to "embed" the mat sounds like entirely too much work. I would definitely go the SLC route if I were gonna do that. It sounds like a lot of people on here prefer to embed the mats in something, is it necessary to do so? From what the instructions say you can just trowel over the mat and set the tile.

Thanks for the replies guys. The muddy water is slowly beginning to clear!

[PatM]

I didn't have any problem with sag. It was installed on backerboard using thinset and following their directions. I was VERY CAREFUL troweling the thinset over the mat and wiring even though it is teflon coated and should be pretty tough. Attached is a photo of the kitchen. Disregard the missing spaces around the border/band as I miscalculated and Lowes was out the mosaic for a few days. Good luck and warm toes.
Pat

[elsieCat]

May I piggyback a question in this topic? I read at one of the sites (was it Suntouch?) that you can install the mats under a shower floor...My question: is this only if you're doing the traditional mud floor and not a Kerdi membrane? If you *can* use it with the Kerdi system, at which point would you put it, in the bathroom floor sandwich?

And as far as installing this and then leveling out the areas without the mats--is it that you cut little channels for the thicker wires, and then depend on the SLC (can you use SLC with Kerdi?) to cover over the mats and level out the 1/8" unevenness?

Thanks very much. We're getting closer and I need to get all the details set.

[flatfloor]

Jeff, unless you have a serious height problem your making a hell of a lot of work for yourself grinding out troughs for the wire. Just hot glue them in place then use either thinset or a SLC to imbed them. Then come back and install your tile with thinset. What size tiles are you using? I'll bet large since they are so popular these days. These large tiles require a very flat surface.

Elsie may I suggest you start a separate thread so we can give you our undivided attention. Betcha you will have lots more questions

[elsieCat]

O.K., Jim, I will--I did have a thread around here at some point (about stumping the deflectometer) but I figured it had scrolled off...you're right, btw, I *do* have more questions--how did you know?

[MarcusEngley]

Hi Elsie,

Here you go:

Your old thread...

Just post to that and it'll bump back up...

[elsieCat]

Thanks, Marcus--I'll ask on the other thread how you found it

[jphavener]

Jim,

The power leads on the Suntouch mats are quit large. They require some sort of trough to run them in because they are larger than the mat and/or the heating wire. I'm not gonna run a 20' trough or anything just maybe 1'-2' at the longest. I could also just chisel it out. I guess I could also just pull the heating wire out of the mesh so that I can run only the heating wire from the baseplate and not had to run the power wires across the floor. I think I will seriously consider that.

I'm only using 12" tiles in the bath. I considered larger but I know that flatness matters and I didn't want to mess with that and the heating mats.

I'll tell you my biggest problem, I'm an engineer and I tend to examine everything too much. I try to know exactly whats going to happen during the process and while that helps sometimes, it can be a pain too.

Thanks,
Jeff