I have visited several tile stores and received conflicting subfloor thickness requirements.
Subfloor thickness for ceramic tile.
This number is known as a span rating.
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.
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.
Subfloor holds up all of the above layers of flooring as well as everything in your house people dogs cats pianos furniture.
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.
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.
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 subfloor must be structurally sound as well as thick and stable enough to hold the weight of the tile without moving or flexing.
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.
Regardless of the material it must be at least 1.
The subfloor is 5 8 t g.
We are planning on using ceramic tile with granite counter tops.
Most of the cabinets are on the perimeter on the room with a peninsula that runs to the center of the room 7 from the outside wall.
The thickness of plywood panels in a subfloor is regulated by the spacing of the joists.
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.
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.
An extra layer of ceramic tile adds substantial thickness to the flooring layer.
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.