Tips for Installing Tile Floors
When having tile flooring installed you must have a very strong sub-floor on which to lay them. Without 1 ¼” of plywood sub-floor, the tiles will eventually crack. If you are the unlucky type, this may happen once you are out of your contractor’s labor warranty (1 year in most states).
Your contractor should inspect the floor to determine if it is strong and not spongy:
- With a strong sub-floor- Still request a ½” plywood sub-floor to be added on top of the existing floor.
- With a spongy sub-floor- Ask your contractor about removing the sub-floor and inspecting the joists. Very rarely will joists have to be replaced. If there is termite or water damage, a common technique is to ‘sister the joists’ (run an additional plank along side of it for more support).
Also, blocks (pieces of wood running perpendicular to help stabilize the joists) may need to be added because they were not always used in old construction. If the joists prove to be strong, then the sub-floor was weak. Adding a new 3/4″ sub-floor on top of the joists, then an additional 1/2″ plywood sub-floor on top of that may help. Be sure that your contractor does not line up the ‘seems’ of the two layers, lest the floor may be weak.
Be wary of:
- Tile backer board- (commonly referred to as Durarock; a brand name) this is meant for tub/shower wall applications and does not have the same strength as plywood.
- OSB- (oriented strand board, or wafer board).
Note: When using marble or exotic stone ask your contractor if he is familiar with ‘floating the stone.’ Exotic stones vary in thickness and he will have to sink the thicker tiles deeper into the thin set (glue). If he is not familiar with this, you should be concerned.