Ceramic Tile Over Plywood Subfloor

Subfloor with a crack isolation membrane under the tile.

Ceramic tile over plywood subfloor.

According to backer board manufacturers and tile setters installing backer board directly over an old solid wood subfloor is risky for a couple of reasons. 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. No matter how firm the subfloor. The tcna spec shows this detail with the tile bonded directly to the plywood but few tile experts recommend doing this.

Because of issues of moisture movement and adhesion ceramic tile will work well with certain types of subfloor underlayment systems and can go dramatically wrong with other subfloor materials. While you can lay tile directly over a concrete slab using thin set adhesive don t make the mistake of applying tile directly to a plywood subfloor. A poor ceramic installation will delaminate from the subfloor split at the grout lines or worse crack directly across the tile. One question that folks new to ceramic tile frequently ask is whether they can lay the ceramic directly on top of a plywood or osb subfloor using a thinset cement or liquid nails to glue down the tile to the wood.

Another tcna method f147 uses a min. 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. With this patented new technique ron s friend shows us how to build a strong base and then prepare it using the tavy thin skin system so that the tile is as strong. When installing a ceramic tile floor on a concrete subfloor you don t have to worry about flexing as long as the concrete slab is at least 1 1 8 inch thick which most slabs are.

Laying tile over a plywood subfloor can be a bit tricky but if you take the time to prepare the sub floor properly you can enjoy a new tile floor that will last for a lifetime. Concrete expands and contracts and that type of movement can also crack the tiles and the grout. First changes in humidity make solid wood shrink swell and cup more than plywood. The best method is to refasten the subfloor then add a layer of plywood.

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. For this reason ceramic and porcelain tile floors can be considered somewhat delicate despite the inherent strength of the material. However you re not out of the woods. But a number of precautions must be taken to ensure a successful installation.