Can ceramic tiles be laid over wood?
Although it is possible to fix tiles to exterior grade plywood, and ceramic tiles are installed over wood occasionally, laying tiles directly on wood is not recommended. Tiles are never installed over plywood on an exterior application or in any area which gets wet frequently as the wood expands and warps when it gets wet causing tiles to fracture. Concrete is the best surface to bond ceramic tile or stone. The best method of concrete bonding is to use the mortar bed method but if this can’t be done then install the tiles over a cement backer board. If there is no other choice tiles can be bonded to wood but it is imperative that it is done correctly. When installing on wood make sure the deflection of the floor is no more than L/360 for ceramic tiles. Two layers of 5/8″ plywood is recommended on joints spaced at 16″ on centre. You can use a modified epoxy to bond the tile to the wood or a latex or polymer modified thin-set.
