Radiant heat question

tpagel · 05-19-2008, 09:08 PM

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.

warmsmeallup · 05-20-2008, 08:51 PM

Yes, electric would be the better choice. If you're using it just tp warm the floor it would be fine to install it without an insulator, however, if you can use it, it would benefit the design.

You can look into low voltage "Floorizwarm" systems from Heatizon and line voltage mats from Danfoss. They are both good products. The major difference is the repairability aspects of low voltage if damaged in the future. Line voltage mats are next to impossible to repair.

tpagel · 05-21-2008, 01:04 AM

Thanks for all the advice here. I think I have decided to simply recondition the slab, apply a cork sheet underlayment and then a floating cork plank flooring on top of that. The cork material is decent for acoustic and thermal insulation, as well as a "softness" underfoot and great durability. When in doubt, simplify!

Steven62 · 05-21-2008, 03:43 PM

I agree somewhat with what is said here, but must differ with the statement that "line voltage systems are nearly impossible to repair". I work for Watts Radiant (Suntouch) and have guided thousands of people thru the process of repairing the wire, which is line voltage.
It is usually more difficult to locate the damaged area than it is to actually repair it, and of course, an ounce of prevention is worth a pound of cure, most of these folks either didnt read the manual, didnt have an Ohm meter or "Loud Mouth" or both.
That being said, although I work for a radiant floor heat company, I really like cork floors!

warmsmeallup · 05-21-2008, 05:57 PM

Watts does make a nice product. And, yup, that's why I didn't say it can't be repaired. As you said, finding the break through the shielded wire is the part that makes it next to impossible...but not impossible. In 3 years of selling and installing low voltage systems, I've never had to walk anyone through a repair.

I have had to find the element to splice in additional wire so the homeowner could have a heated shower seat after the tile was installed, but that just took a tic tracer.