TILING ONTO WOOD OR CEMENT-FIBER BOARD
Supported structure is the most important thing to consider for tiling onto wood or cement-fiber board. Make sure that the floor will be capable of supporting the expected load. It must be stable and well supported. In addition special products designed for tiling onto these specific substrates should be considered to use.
Common issues and queries you can face

1. Deflection according to applied load
Timber floors or cement-fiber boards will deflect according 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.

2. Inadequate supported joint
Any inadequate supported joint will cause a highly localized movement which will crack the tiles. Joints have to be filled up with special silicone sealant to support the localized movement and also to support the substrate expansion.

3. Substrate's expansion and contraction
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.

4. The rate of expansion and contraction
Temperature and moisture/ humidity affect the rate of expansion and contraction. 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.