Wall Tiling – Plywood

For wall tiling applications it is essential that the wall itself has sufficient inherent strength to hold the proposed tile and the adhesive being used.

The following chart lists the accepted maximum loadings for a variety of wall substrates. In all cases, it is advised that where wall boards, of any type, are used that the manufacturer be consulted for further guidance.

Wall Substrate Maximum tile weight (plus adhesive and grout*)
Gypsum plaster 20kg/m²
Plasterboard (gypsum) unskimmed 32kg/m²
Plywood (exterior grade) 30kg/m²
Gypsum fibre boards 40kg/m²
Tile backer boards 40kg/m²
Glass reinforced cement sheets 50kg/m²

*Typically the weight of the adhesive and grout is 2-4kg per m².

Wall types vary considerably but all have the same basic need to be structurally sound, strong, smooth and level.

It is important to understand that tile adhesives are not designed to be a method of overcoming surface undulations and unevenness.

The specifications for various substrates and their stability are listed below. Should any other substrates be encountered, please contact the UltraTile Technical Department.

Plywood

A – Studwork walls
B – Plywood (it is recommended to seal all exposed plywood to ensure any high/low humidity fluctuations do not cause warping and distortion)
C – Prime (if using a ready mixed adhesive priming may not be necessary)
D – Apply adhesive (selected upon tile type)
E – Install tiles
F – Grout all joints

Instructions:
Plywood boards must be a minimum thickness of 15mm. The grade of plywood used should be suitable for exterior use and may include marine or Class 3 plywood. The boards should be fixed to the framework at a minimum 300mm centres on both horizontal and vertical battens. The plywood must be screwed, not nailed to the framework to ensure a rigid, secure substrate. Any supporting timber framework must be fully seasoned to ensure no warping or twisting occurs after installation.

Priming:
Is not normally required with highly flexible adhesives. If in doubt please consult the UltraTile Technical Department.