When installing tile over a plywood subfloor, 1/4-inch cement backer board is typically sufficient. This thickness offers the necessary stiffness and moisture resistance for floor tile without raising the floor elevation significantly, which is important for keeping floor transitions level with adjacent rooms. Thicker board, such as 1/2-inch, is more commonly utilized for wall applications or shower enclosures where structural strength or bridging over specific studs is required. It is essential to follow the manufacturer's specific instructions regarding the installation of their backer board. This includes using the correct mortar bed underneath the board to ensure full contact and support, which eliminates hollow spots. If your subfloor is not rigid enough, simply adding backer board will not compensate for the deflection. If you notice floor movement or springiness, professional inspection of the subfloor joists is necessary before beginning any tile installation.
Key considerations
- backer board thickness
- tile floor underlayment
- cement board size
- 1/4-inch Board
- Cement Board
- Subfloor