Putting Subfloor Over Ceramic Tile

Contractor rob robillard addresses readers questions about putting hardwood or laminate flooring over tile and dissuading birds that want to live in your exhaust fan.

Putting subfloor over ceramic tile. Concrete expands and contracts and that type of movement can also crack the tiles and the grout. A subfloor is the bottom most structural level of your floor. It supports your decorative floor finish whether it s carpet hardwood vinyl laminate or tile. 2 check the height difference the.

Installing ceramic floor tile to a plywood sub floor has unique challenges beyond that of installation on a concrete floor. For this reason ceramic and porcelain tile floors can be considered somewhat delicate despite the inherent strength of the material. 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. Read on to find out more.

But there are a few important considerations to take into account when tiling over a wood subfloor. No matter how firm the subfloor. 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. 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.

Plywood or osb flakeboard can expand and contract at too high a rate to be a stable foundation for tile. The use of a plywood subfloor topped by cement backer board has made tiling much easier today than when i started my remodeling career. The goal is to have a wooden subfloor consisting of two. 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.

This will cause either the tile itself to crack and even come loose or cause the grout to crack inside the joints. Measure and cut 1 4 inch or thicker plywood with a circular saw to fit the entire floor of the room where you are installing vinyl flooring. However you re not out of the woods. Preparation for installing floor tile depends on the type of subfloor in the room you are tiling.

For more information download our pdf about types of subfloors. However if you can t remove the old surface or otherwise decide to install over it lay a backer board with thin set over the old surface to serve as your new subfloor material.