How to Lay Ceramic Tile Over Heat Coils

Heated tile floors are a luxurious home improvement.

Stepping on cold tile in the bathroom or kitchen is no way to start your day. Throw rugs help, but it's easy to accidentally step on the cold tile floor, especially if you haven't had your first cup of coffee. A heated floor is a luxurious improvement to your home. Mats with heating coils attached simplify installation and can be installed on any subfloor that is appropriate for ceramic tiles.

Things You'll Need

• Electric heat mat
• Heat mat alarm
• Thinset
• Notched trowel
• Self-leveling compound
• Chalk lines
• Ceramic tiles
• Tile spacers
• Grout
• Float
• Sponge

Instructions

1. Select the right heating mat for your floor. If none of the many stock sizes available are appropriate for your floor, you can have one custom made. You cannot cut the heat mat to size since that would require cutting the embedded heating coils. Heat reaches beyond the edge of the mat, so leave 4 to 12 inches of space between the edge of the mat and the wall. You must also leave 12 inches between the mat's edge and the toilet flange to keep the heat mat from melting the wax seal at the base of the toilet. Not all heating coils are compatible with ceramic tiles, so check with your supplier.

2. Attach the heat-mat alarm to the mat's lead wires. The alarm will sound if you ding a heating coil while you work. A damaged coil will not heat up. If the alarm sounds, straighten out the coil before continuing. If you are unable to fix the coil, you will have to replace the entire mat.

3. Lay the heat mat on the subfloor with the lead wires near the exit. Fold back one half of the mat and spread thinset on the subfloor. Comb the thinset with the edge of your notched trowel to make grooves. Fold the mat back down onto the thinset and gently press it into the thinset with a grout float. Press just until the thinset oozes between the heating coils. Repeat for the other side of the mat. Let the thinset dry overnight.

4. Prepare the electrical connections according to the manufacturer's instructions. Different mats have different instructions, but generally you will need to position wires for electrical power and the heat sensor so that they can be hooked up after the ceramic tile has been laid. Don't let the wires touch the heating coils, or they could become damaged by the heat.

5. Pour self-leveling compound on the floor and spread it around with a grout float. Allow the self-leveling compound to dry according to the manufacturer's instructions. Disconnect the heat-mat alarm.

6. Proceed as you would for any other tiling project. Snap chalk lines on the floor to guide you when placing the tiles. Spread and comb thinset on the floor with a notched trowel. Place the tiles with spacers on all sides. When the thinset has dried, spread grout over the tiles, filling all the spaces in between. Wipe the grout from the tile surface with a wet sponge and joint the grout by running the edge of a damp sponge along all the grout lines.

Tips & Warnings

• Do not walk on the floor while the thinset is drying or you may damage the heat coils.

• Be careful when you stepping or kneeling on the heat mat to lay the tiles to prevent damaging the coils.

References

• "Tiling"; Josh Garskof; 2009