Tiling Over Plywood Underlayment

Begin by applying the thin skin adhesive to the plywood with a smooth trowel.

Tiling over plywood underlayment.

If the structure is adequate the use of a cement based floor patch that allows for the needed height may be the best choice. No matter how firm the subfloor. Roll on a layer of latex primer sealer. Tape over holes and cracks in the wood subfloor or slab before pouring on the self leveling tile underlayment to keep it from seeping through and leaving indentations.

Use intervening layers of two sheets of 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. The go to product is 1 2 in. For residential use one form of underlayment the tile council of north america s handbook allows is plywood over joists that are 16 in.

Use thinset with a higher latex content thinset is the wet base that you first trowel on the plywood to make the tile stick. Fill seams in the subfloor with caulk. While tile can be laid on plywood do not install tile directly onto the plywood subfloor itself. Once properly in place and cured the tile can be installed.

Step 5 skim coat the paper. Tape off any affected vents with painter s tape. Once the surface is completely covered cover the adhesive with the fiberglass based paper and smooth out any wrinkles or bubbles with a broad drywall knife. 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 and tile for the thin set adhesive to achieve a good bond.

A tapered piece of plywood may be difficult to fabricate and may not offer the support required for a good installation.