Ceramic Tile Over Plywood

Before laying tile over any plywood subfloor it s important to make sure that the floor itself is free from excessive deflection or bending which can pop grout joints and loosen or crack tiles.

Ceramic tile over plywood.

This guide will show you how to prepare your subfloor for a tile installation project to ensure that it s fit to support ceramic or porcelain tile. Regular seasonal humidity shifts are significant enough to make the average 10 x 10 wood subfloor floor expand or contract as much as 1 2. On a plywood subfloor you need either a layer of cement backer board or an underlayment membrane like custom building products wonderboard and redgard between the subfloor. Ceramic tile doesn t expand contract nearly as much.

If possible you should always use concrete board underlayments rather than plywood. Plywood and osb expand and contract with humidity and temperature much more than ceramic tile. A glass of water can detect deflection that s otherwise hard to see with your eye. Lay down a vapour barrier overtop the concrete pad then fasten 3 4 inch plywood using a ramset to the concrete pad through the vapor barrier then install the heating system to the plywood followed by applying the self leveling mortar over top the heating system and plywood and finally installing the tiles over top that.

The preferred method for tile installations is to use a sheet of underlayment. While most floor tile these days is installed onto a layer of cement board or similar backerboard it is possible to lay tile directly over plywood. A number of different types of substrate are used for tile including plywood. The plywood will expand and contract at a different rate as the tile causing cracks to develop in the grout lines or tiles over time.

For wall installations plywood is overkill beneath the concrete or fiber board which is designed in five eighths inch material for wall settings. As the plywood or osb expands the ceramic won t. Installation of ceramic tile over plywood substrates with latex portland cement mortar tb22 all wooden flooring when placed over conventional floor joist or other systems should be of a design and thickness so as to maintain a substrate deflection not to exceed 1 360th of span including live and dead loads. No matter how firm the subfloor.

Chipboard cushioned vinyl flooring particle boards of any type oriented strand board osb interior grade plywood tongue and groove planking and hardwood floors are unsuitable substrates for direct installation of ceramic tile. To install ceramic tile over wood the wood surface must be structurally sound enough to support the weight of the tile. Preparing a subfloor is an essential step for installing floor tile it provides a level surface that will allow the tiles to properly stay in place.