Putting in either a thermal wire/mesh (SunTouch) type underfloor heater or carbon film under tile.

The subfloor is OSB. Going to pour 3/4" of LevelQuik Self-Leveling Concrete (replacing Gyp-Crete that was removed) and then thinset and tile. Which is the proper layer for the underfloor heating to go in? Energy efficiency is of minimal importance.

Pro of putting it in the concrete is it would survive a re-tile job, possibly? Whereas putting it in the thinset below the tiles means it's junked during a retile. My only worry is that it wouldn't heat properly if it was in the concrete layer.

  • thermosoft has a bunch of videos on installation. I installed under a wood floor but I saw the videos on tile as well. also, fyi, they offer good deals if you say are a contractor. (I'm not a rep...I've installed two floors with their electric radiant). One more more point: follow the manufacturers recommendations....
    – ssaltman
    Feb 23, 2016 at 19:36

1 Answer 1


With the sun touch it goes on a mat under the backer or cement. The thicker your space to the tile is the more even the temp will feel and it won’t be bothered if you decide to retile. I thought it was so nice I put it im 2 of my bathrooms.

  • if the thinset is poured into the heater's mesh mat, during a re-tile how could the old thinset be separated from the heater?
    – user345807
    Feb 23, 2016 at 19:45
  • The heat mat is 1/4" to ? below the surface of the cement so you can chip the tile up. Mine is 1" in the first bathroom and ~1-1/4 in the second bathroom in my house. The remodels we did were at most 1/4" and you can tell the difference. But they all feel nice to bare feet in the morning. (The mat under the sun touch was the insulation layer they recomended)
    – Ed Beal
    Feb 23, 2016 at 19:53

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