The builder hired used 3 4 osb for the flooring while the tile contractor used a 1 4 cbu under the tile thus achieving 1 in total depth.
3 4 inch plywood for tile floor substrate.
To cut backer board measure and mark the size you need.
The average thickness of plywood sheets used for backer on counter tops is 3 4 inch.
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.
Now the entire flooring of ceramic tiles needs to be torn out and replaced.
I built a home about 7 years ago that is having all kinds of problems with the tile flooring cracked tile displaced grout creaky flooring 1 2 deflection in some areas.
You can use it as a stand alone product as well as a finish type plywood if it has a laminate finish that you can paint or finish according to personal preference.
It typically comes in 4 x 8 foot sheets.
Most prefer a minimum thickness of at least 1 1 4 inch such a inch t g subfloor with inch plywood underlayment.
The floor tiles became loose cracked and ugly looking over about 2 decades of use.
Thin set was used instead of glue or adhesive.
Now largely regarded as the very best underlayment for ceramic tile in any application floors walls and countertops cement based backer board goes by many names.
Continue this process to lay the rest of your backer board panels leaving a 1 4 inch gap at the walls.
This provides adequate support for a wide range of finish materials.
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.
It is generically called cement board or backer board or it can also be referred to by one of the common brand names such as densshield hardiebacker and wonderboard.
Most plywood underlayment is about 1 4 inch thick and has square edges and a smooth knot free top face.
Use 16d common nails to create a gap of 1 8 inch between the sheets.
Backer board panels typically measure 3 feet by 5 feet and can be trimmed as needed.
Leave a gap of 1 8 inch between sheets for thin set mortar or tile.
Cement based backer board.
The bare minimum recommended by most tile setters is a total subfloor thickness of 1 1 8 inch.
Use 5 8 inch thick exterior grade plywood placed with the smooth side up and the top grain perpendicular to the floor framing.
Adding inch plywood to 5 8 ply will give you a combined nominal thickness of 7 8 inch.
For many years the standard option was lauan plywood also called philippine mahogany or luan plywood which is made with an inexpensive tropical hardwood and therein lies its problem.