Plywood Subfloor Thickness For Ceramic Tile

A 3 4 inch plywood subfloor on a joist structure with 24 inch spacing needs the extra thickness of cementboard or the floor will flex and the tiles will crack.

Plywood subfloor thickness for ceramic tile. Hoping for some advice on a ceramic tile installation over 5 8 plywood subfloor on the second floor of our 1974 split level house. Uncoupling membranes aren t recommended for tiles smaller than 2 inches square and should not be used when covering old hardwood flooring due to adhesion problems. Diamond tipped blade the diamond grit bonded to the edge of these steel blades lasts up to 30 times longer and cuts twice as fast as carbide grit. Joists are 11 5 12 footers.

The safest most prudent course is to install tile on top of a cement backerboard such as durock wonderboard or hardiebacker. The subfloor must be structurally sound as well as thick and stable enough to hold the weight of the tile without moving or flexing. The minimum thickness allowed for ceramic tile installations is two sheets of 5 8 inch thick plywood. Backerboard does not shrink or expand when it comes into contact with water mortar and grout both contain water.

The bare minimum recommended by most tile setters is a total subfloor thickness of 1 1 8 inch. This number is known as a span rating. 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. Yes you need at least 9mm thick plywood on bathroom floorboards screwed down prior to floor tiling layed with flexible floor tile adhesive.

Adding inch plywood to 5 8 ply will give you a combined nominal thickness of 7 8 inch. I say 11 5 12 because i never took the whole floor up to measure and the. The subfloor under the tile should be at least 1 1 8 thick with a minimum of 5 8 thick exterior grade plywood topped by 1 2 cement backer board. The thickness of plywood panels in a subfloor is regulated by the spacing of the joists.

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 plywood must be exterior grade for all wet areas and it has to be installed in such a way that the joints between each layer do not line up using what is known as a stagger pattern to keep the pieces from ever lining up. However they do have some bearing on top of partition walls below. Regardless of the material it must be at least 1.

Most prefer a minimum thickness of at least 1 1 4 inch such a inch t g subfloor with inch plywood underlayment. Plywood substrate alternatives. When installing a plywood subfloor on top of the slab at grade.