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.
Ceramic tile plywood subfloor installation.
Laying tile on plywood.
The tcna spec shows this detail with the tile bonded directly to the plywood but few tile experts recommend doing this.
However you re not out of the woods.
Plywood substrate alternatives.
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.
To install ceramic tile over wood the wood surface must be structurally sound enough to support the weight of the tile.
No matter how firm the subfloor.
Tile floors are heavy and tile is a hard material.
Backerboard does not shrink or expand when it comes into contact with water mortar and grout both contain water.
Installing ceramic floor tile to a plywood sub floor has unique challenges beyond that of installation on a concrete floor.
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.
Remember that you need a very flat surface to work on.
Installing over wood.
Concrete expands and contracts and that type of movement can also crack the tiles and the grout.
Cement backerboard is made for tiling.
If needed sand the plywood down to level the subfloor.
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.
The detail shown is essentially tcna s f150 method with the addition of an uncoupling crack isolation membrane.
A poor ceramic installation will delaminate from the subfloor split at the grout lines or worse crack directly across the tile.
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.
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.
The safest most prudent course is to install tile on top of a cement backerboard such as durock wonderboard or hardiebacker.
Plywood or osb flakeboard can expand and contract at too high a rate to be a stable foundation for tile.
It will break or dislodge if the surface bends under the load.
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 plywood subfloor must be structurally sound and able to support the installation.