Is my subfloor ready for tile?
A subfloor is ready for tile when it is stiff enough not to flex underfoot, flat enough for the size of tile you picked, and clean and dry. The bigger the tile, the flatter the floor has to be.
- Stiffness: a floor that bounces gets reinforced before any tile goes down
- Flatness: checked with a straightedge; high and low spots are fixed, not tiled over
- Clean and dry: no old adhesive and no unresolved moisture
- Movement joints: needed at the walls and across large areas, where many cracked floors started
- Uncoupling membrane where the floor calls for it, especially over concrete slabs


