How to Install an Underfloor Heating Mat Part 3 How to Install an Underfloor Heating Mat Part 3
When the underfloor heating mat has been laid out and attached to the subfloor, you are ready to prepare to lay the tiles. In this section of our installation guide, you will learn how to connect the thermostat, spread thinset (tile mortar) and get ready for tiles. Let's get started.
Step 1 - Connect Heating Conductor Wires to Thermostat
Although you should let a qualified electrician do the actual wiring of the thermostat to a power source or your main circuit breaker, you can go ahead and connect the heating conductor wires to the thermostat. If you're heating mat kit comes with a floor sensor wire, you can connect it as well. Look in the instruction manual for your heating mat kit and follow the directions for connecting the wires to the thermostat.
Step 1 - Purchase Enough Thinset Mortar Mix
When purchasing thinset mortar mix for your tile installation over the heating mats, keep in mind that radiant heating floors will require about 50% more than standard cold floors. So, when purchasing thinset, plan accordingly.
Step 2 - Mix the Thinset Mortar
Pour water into a large bucket until it is about one quarter of the way full. Next, pour dry thinset mortax mix into the bucket. Don't pour too much mortar into the bucket to begin with, but rather add mortar mix gradually. Next, start mixing the thinset and water slowly with a paddle. Continue mixing until the mortar mix and water are blended thoroughly. Add mortar mix or water as needed until the mixture is creamy and has a consistency that is easy to work with and not too runny or watery. The consistency of the mixture should be similar to mud that is not dried out or too loose.
Step 3 - Apply Thinset Over Heating Mats
Use the flat edge of your mortar trowel and begin spreading the thinset over the heating mats. Spread the thinset mortar evenly and slowly. Make sure the thinset mortar completely covers the mesh and wires of the heating mats and also that the surface of the mix is fairly smooth. Be extra careful not to damage the heating mats when applying mortar mix. Work in sections and spread mortar mix 12 to 18 inches wide. Don't spread too much thinset mortar at any one time as it may dry out before you can place the tiles.
Step 4 - Create Trowel Notches in Thinset for Tiles
After covering the heating mats with thinset mortar, quickly use the notched side of the trowel to create rows of notches in the wet mortar mix. Work quickly, but also be careful not to dig the trowel too deep into the mortar mix or you may damage the heating element of the mats. When using the notched side of the trowel, the trick to success is skimming the surface of the mortar mix and not applying too much pressure.