TILING ONTO WOOD OR CEMENT-FIBER BOARD

Some limitation of timber substrates and cement-fiber boards such as flexibility and water absorption need to be considered when fixing rigid tiles onto these specific substrates.

Problem

Timber floors will deflect to the applied loads.

Make sure that the frame, which could be either metal or wood, is strong enough to support the expected load. Screwing joints at every area of 30X30 cm can help to increase the rigidity of the floors.

Inadequate supported joint will cause a movement.

Joints have to be filled up with special silicone sealant to support the localized movement and also to support the substrate expansion.

Expansion and contraction of the substrate

Woods and cement-fiber boards expand and contract with changes in ambient-temperature at a different rate to adhesive, grout and ceramic tiles. If the adhesive is not able to absorb the expansion and the contraction, the crack in adhesive layer can happen and then the tiles will delaminate. Flexible adhesive together with appropriate primer must then be considered to use for this case.

Temperature affect the rate of expansion

Woods and cement-fiber boards swell if getting wet and contract when water evaporates. Even though cement-fiber board can be externally used but it should be tiled over because of the extreme weather condition. Woods and cement-fiber boards should be only internally used for tiling over.