Plus they offer an additional benefit over plywood including increased weight limits for tiling.
Tiling onto plywood wall.
Use thinset with a higher latex content thinset is the wet base that you first trowel on the plywood to make the tile stick.
For wall installations plywood is overkill beneath the concrete or fiber board which is designed in five eighths inch material for wall settings.
As plywood goes under a continuous change in size tiles and grout can crack and cause irreversible damage.
It contains oils that are sensitive to temperature changes.
If possible you should always use concrete board underlayments rather than plywood.
You may tile over existing tile painted or unpainted drywall plaster and textured walls.
However tiling onto plywood floors is still acceptable under british standards.
However tiling over tile can add quite a bit of thickness so make sure your wall can handle the weight.
While tile can be laid on plywood do not install tile directly onto the plywood subfloor itself.
If you re not sure if you have lead paint test kits are available.
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.
You can use plywood for tiling floors but when it comes to walls it is unfit.
Tile backing boards are ideal for wall tiling as they offer a dimensionally stable wall background to moisture and thermal movement.
The preferred method for tile installations is to use a sheet of underlayment.
Use intervening layers of two sheets of plywood.
The recommended maximum weight of tiling for plywood is 30kg m.
The heat will only loosen the grip of the adhesive.