What changes when a floor gets heat?
A heated floor adds mats or wires to the tile assembly, so the floor needs protection, flattening and height planning before tile is set.
Heat wires should not create ridges under the finished tile. Depending on the system and floor, floor leveling with self-leveling compound may help create a flatter surface over or around the heat layer.
Subfloor preparation for tile still matters first because heat cannot make a moving or damaged floor suitable for tile.

