Published on October 3rd, 2012 | by Henri0
Radiant heat in bathroom
Q. We are remodeling an 8-foot by 10-foot existing bathroom. It is an inside room and will contain a separate tub and shower. We are considering a tile floor with a SunTouch Radiant Heat Mat. These mats are heated electrically and the manufacturer states that they have a very low energy usage. We have several questions: 1) What is your opinion on the overall reliability of these units? 2) If they fail, do you need to tear out the floor (there is an unfinished basement underneath this bath)? 3) Would the floor unit be enough to heat the entire bathrom?
A. The type of floor mat you are considering is recommended by my old friend Mike Byrne, an expert tile setter who has written several books and conducted many educational workshops for the tile trade.
The critical issue in installation of the electrical mat to ensure that the system is working properly throughout the various installation steps. This involves the electrician checking the electrical resistance before the matting is installed, again before a self-leveling compound is spread (this step is advisable if small tiles are used, for instance), and once more before the tiles are installed. The matting should be kept 6 inches away from the walls, 12 inches away from the toilet (to avoid melting the wax seal) and it must not be installed under any furniture or furnishings (this would cause overheating and could lead to failure).
If there is eventual failure, the tile floor will have to be removed and the system replaced; it cannot be accessed from below.
It is best to use large tiles as they cover several strands of the heating wires and simplify the installation. Smaller tiles are more likely to tip as they do not bridge over several wires resulting in an uneven surface.
The system uses very little electricity and should be enough to provide the needed comfort for the bathroom if you time the thermostat to activate the system for the family’s bathing habits. The thermostat can also be activated at other times, with comfort assured so long as you turn it on far enough in advance to heat the floor.