Underlayments
Have you ever wondered why tile can’t just be installed over the sub-straights of your home?
It is not recommended to install tile directly on your wood sub-straight (decking) for several reasons. The wood sub-straight will absorb some moisture from the thin-set which can cause it to weaken. Plus, if you have movement in the floor, your grout will crack or break out. So can your tile. A proper sub-floor will also help with a microbial barrier, reducing mold & mildew, and create water resistant surface.
Tile cannot be installed over other flooring products either as the stability of the sub-floor is crucial to the strength and durability of the tile.