Wall Tiling – Plaster / solid walls / skimmed plasterboards5th February 2016
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*)|
|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.
Plaster / solid walls / skimmed plasterboards
A – Block work wall construction
B – Plaster (do not tile onto bonding/backing plaster)
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
A plastered wall must be at least four weeks old prior to tiling to ensure adequate strength build up and suitable dryness. Prior to tiling ensure the plaster is dust free and is not showing any signs of efflorescence. Weak or friable plaster should not be tiled onto. Densely finished, polished or shiny plaster should be ‘roughened’ up to provide a good mechanical key. A stiff bristle brush should be used.
Apply 2 coats of UltraTile Prime IT FP (diluted 3 parts water to 1 part primer) or UltraFloor Prime IT Multi-surface Primer, allowing each coat to dry before continuing.