Subfloor Thickness For Ceramic Tile

Regardless of the material it must be at least 1.

Subfloor thickness for ceramic tile. An extra layer of ceramic tile adds substantial thickness to the flooring layer. 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. A subfloor system that worked fine for a single layer of ceramic tile may not be strong enough to handle the many hundreds of extra pounds added when a second layer is added. 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.

We are planning on using ceramic tile with granite counter tops. The subfloor is 5 8 t g. With ceramic tile you also need to limit the deflection between joists which is a function of the subfloor thickness and how it is installed. Typically made of plywood or osb and ranging in thickness from 19 32 to 1 1 8 thick the subfloor is truly structural second only to joists in this respect.

I have visited several tile stores and received conflicting subfloor thickness requirements. Subfloor holds up all of the above layers of flooring as well as everything in your house people dogs cats pianos furniture. 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. The thickness of plywood panels in a subfloor is regulated by the spacing of the joists.

Preparing your subfloor for tile in this video learn how to prepare a wood or concrete subfloor for tile including such steps as checking for dips installing backerboard applying primer and thinset pouring liquid underlayment and when to use osb or exterior grade plywood. 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. When installing a plywood subfloor on top of the slab at grade the. 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.

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 subfloor must be structurally sound as well as thick and stable enough to hold the weight of the tile without moving or flexing.