Ceramic Tile Over Luan Plywood

Plywood underlayment is a thin plywood material that is most commonly used under resilient flooring materials such as vinyl and linoleum sheets and tiles.

Ceramic tile over luan plywood.

Luan plywood is an unacceptable and unapproved substrate to receive tile or cementitious backer units cbu. The seams between vinyl tiles allow water from spills or mopping to soak into the luan which can result in swollen plywood and lumps that are visible on the surface of the vinyl floor. Luan is a hardwood species containing extractives sugars. Wood based panels such as particle board composite panels veneer faces bonded to reconstituted wood cores luan plywood and soft wood plywood all expand and contract with changes in moisture content and are not recommended as backing materials for ceramic tile.

I just finished prepping my 16 x 16 kitchen for ceramic tile. Plywood in ceramic tile installations. The books says a minimum of 3 8 underlayment grade plywood no 1 4 then use ditra or a 1 4 cement backer board both are installed in a wet bed of thinset. It can also be used under hardwood laminate and carpet but this is much less common these days because subflooring is typically smooth enough for these materials many of which are installed with a different type of underlayment or pad.

Never have that under tile. Ceramic tile stone and or cementitious backer unit installations utilizing any luan species will not be warranted by custom.