For wall installations your real concerns are whether you want to use thinset directly on the wood and whether you are using an exterior or interior type of plywood.
Ceramic tile directly on plywood.
Using adhesives as per the tile you are wishing to place is.
Ceramic tile doesn t expand contract nearly as much.
Backerboard can double the thickness of an installation which can be troublesome in some locations.
While most floor tile these days is installed onto a layer of cement board or similar backerboard it is possible to lay tile directly over plywood.
Mastic adheres the tile directly to a wooden sub floor to a wooden back splash or onto a piece of plywood.
Glue called mastic is the least expensive method for installing tiles.
Be mindful to use intervening sheets of plywood before putting tiles on it.
It is more important as a subfloor than anything else.
So it is better to put sheets of plywood before placing the tile on it.
The plywood will expand and contract at a different rate as the tile causing cracks to develop in the grout lines or tiles over time.
To be sure maybe drill up to 6 evenly spread out holes in the plywood at least 4mm deep or straight through in the areas to be tiled so the adhesive sinks into the holes and hardens hence creating a stronger fix.
There may be times when you want to bond tile directly to plywood or another wood surface rather than screwing down backerboard first.
Using intervening sheets of plywood.
A number of different types of substrate are used for tile including plywood.
Plywood and osb expand and contract with humidity and temperature much more than ceramic tile.
Installing tile directly on the plywood can damage the plywood and your tile both.
You may also want to tile an outdoor shed or tile plywood boards for display.
Under british standards bs 5385 part 1 plywood has now been excluded as a suitable substrate material for the direct fixing of wall tiles therefore when tiling on to walls a tile backer board is required however tiling onto plywood floors is still acceptable under british standards.
As the plywood or osb expands the ceramic won t.
But a number of precautions must be taken to ensure a successful installation.
Loose areas on an existing plywood subfloor can cause peel and stick tiles to lift over time.
Regular seasonal humidity shifts are significant enough to make the average 10 x 10 wood subfloor floor expand or contract as much as 1 2.
If you re installing new plywood use galvanized screws to fasten it and countersink the screw heads.
While some types of plywood can be used in certain types of tile installations use of the material has limitations.
While you can lay tile directly over a concrete slab using thin set adhesive don t make the mistake of applying tile directly to a plywood subfloor.