It will break or dislodge if the surface bends under the load.
Proper subfloor for ceramic tile.
For this reason ceramic and porcelain tile floors can be considered somewhat delicate despite the inherent strength of the material.
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.
Tile floors are heavy and tile is a hard material.
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.
Laying tile on plywood.
However you re not out of the woods.
A plywood subfloor must be structurally sound and able to support the installation.
Wood building materials contract and expand at different rates from natural humidity and exposure.
It sounds like your joists are well within the acceptable limits of l 300 so your main concern is the deflection of the subfloor between joists.
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.
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.
Cement backer board can provide a solid flat surface to install tiles on if you have a wood subfloor.