If you must install over such surfaces it is best to install a backer board over the old surface and install the tile on the backer board.
Ceramic tile over wood subfloor installation.
Tile can be installed over a plywood substrate and it is actually a fantastic way to make sure you don t have deflection in your floor.
Cement backer board can provide a solid flat surface to install tiles on if you have a wood subfloor.
According to backer board manufacturers and tile setters installing backer board directly over an old solid wood subfloor is risky for a couple of reasons.
The 2 3 s would be standing up on their side so.
Build a structure of 2x3 s with 8 inches of space between the boards.
Use intervening layers of two sheets of plywood.
Hope you didn t like your beautiful new tile floor.
If installing over an appropriate wood surface sand the wood to make it smoother and remember that the installation will work better over a subfloor at least 1 1 8 inches thick.
A plywood subfloor must be structurally sound and able to support the installation.
While tile can be laid on plywood do not install tile directly onto the plywood subfloor itself.
Second the strength of wood boards isn t always consistent.
Laying tile on plywood.
Lay down inch exterior plywood and screw into the 2 3 s every 8 inches.
First changes in humidity make solid wood shrink swell and cup more than plywood.