Radiant flooring question

tpagel

Looking to renovate existing 1950's kitchen. It is slab on grade and since I was planning on ripping out existing ceramic tile and pouring a self-leveling topcoat rather than recondition the slab, I want to look into using radiant heat for the small area (60 SF) in the center, between the cabinets. Questions are:

1. I have no idea if there is any insulation under the slab or at its perimeters. I had a bathroom re-plumbed, and I believe I saw no insulation when I looked in their drain connection excavation. Does this make radiant heating too inefficient to use? Can I put down a sheet of cork over the concrete subfloor to help with that, and then the electric mat and topcoat over that?

2. The house has hot water baseboard heat, and the heating system is 12' away from the kitchen, but given the small footprint to be heated, isn't electric the way to go?

3. Can anybody give me some radiant mat products that they have used and liked?

Thanks in advance.

angus242

To actually heat the room? Most likely not efficient enough. To just keep your feet warm? It should do an adequate job of that. However, radiant heating through an uninsulated slab will take a while to come to temperature. May also have to cycle often to keep at temperature.

Termite

I've found the electric mats to be quirky and delicate prior to covering. But, they'll keep your feet from freezing. As mentioned, they won't heat the room on their own. You have to take a lot of precautions not to damage them at all during installation.

tpagel

Thanks, guys. Would hydronic heat, with PEX tubing, be any different, or do the same limitations exist?

angus242

I'm not an expert at this but I have been doing a lot of research recently on hydronic as I'd like to install throughout my own home.
I believe your situation doesn't change with whatever your source is. Bottom line, no insulation under the slab.
A solution might be along the lines of adding something like this OVER the slab:
http://www.infloor.com/products/infloorboard.shtm
I can tell you, it's not cheap and you'll have obvious floor height issues. If you can tackle the height difference, it might be a good solution seeing as it's a smaller area.

poppameth

I've been working with several tile guys lately on electric systems for a client. So far the one that comes most highly recommended is Warm Tiles. It's not a mat. Its a series of tracks you screw down and then run a loose coil of element through. It's suppose to be much easier to lay out the floor the way you want it that having to cut the mat systems at certain points and turning it.

Steven62

Pex is better at primary heat, but requires more initial cost in boilers/pumps, and adds more height to the floor (1-1/4" mudbed).

Electric can keep the floor warm, but usually will not provide primary heat. Slabs should be insulated with a membrane made for tile use, that has an R value (actually, K values are more important in this application...But I digress..)

Examples are:
1. Acoustic Cork

2.Polystyrene ( or other formulas) expanded sheeting/film (easy mat. whisper mat etc.)

3. Poly sandwich backer boards.(Wedi, Easy board, Bonsal pro panel)

Basically, as you go down the list the price goes higher and the insalting values go higher as well.
I wouldnt install a radint system over a slab without it. The loose wire systems are less expensive and more flexible as mentioned, and I like the Warm Wire by Watts Radiant (Suntouch).
Be careful that when you choose components that they are compatible.
SLC cannot go over cork or Polystyrene sheets, but can go over the rigid backer board panels!

Have fun with your project, & let me know if you have any questions!

ayeshaa

Here is a guide to types of radiant floor ..
http://www.eere.energy.gov/consumer/.../mytopic=12590

pros and cons of under floor heating
http://ezinearticles.com/?Pros-and-C...ting&id=245723

Here is a picture to picture guide for radio floor installation process
http://www.hometips.com/articles/rad...oor_howto.html


i hope it helps u ..good luck!