• You can create any tile design you want over radiant heating, like heating coils.ceramic tile image by Karin Lau from Fotolia.com
  
  If your bathroom, kitchen or other tile floors feel a little chilly in the morning, install heat coils in your floor and lay tile over the top of them to keep your toes warm. Floor heating coils come in both wire and mat formats, which you can cut to size and use in almost any room. Although you can install carpet and other flooring over heating coils, floor coverings which conduct heat, such as tile and stone, tend to work best.
  
  

Create an Even Surface

• Once you've laid your heating coils down on the floor per the manufacturer's instructions, you must create an even surface on which to lay your tile. A second layer of subfloor, like plywood, can disrupt the heat transfer from the coils, depending on what you use. To keep your floor as efficient as possible, use a conductive element. Pour a self-leveling compound, such as self-leveling concrete, over the heating coils to create an even surface on which to lay the tiles.
  
  

Add a Membrane

• According to Schluter Systems, you should add a membrane or an extra layer between your heating coils and your tile. Membranes can couple with the heating coils or remain a separate piece. Adding a membrane between your tile and your heating coils may slightly diminish the amount of heat that gets through your floor, but a membrane decreases the chances of your tile cracking or getting damaged by the heat in some other way later.
  
  

Use the Right Thinset Mortar

• Before you begin mixing and adding your thinset mortar to lay your tile on the floor, examine the package to ensure you're using the right type of thinset. Certain types of thinset can withstand higher temperatures than others. Since you are constantly heating and cooling your floor, purchase the thinset mortar that will react best and won't crack under those conditions.
  
  

Keep the Heat off

• After you grout your tile, keep the heating coils off. Grout needs at least 10 days to dry and cure completely before the heat is turned on, according to Joe Ferrante of "This Old House." You can use standard grout on your tile floors over radiant heat, but for a longer lasting floor, try a polymer-modified grout. It's more flexible than standard grout and tends to hold up better to the heat fluctuation.