Can I Put 3 8 Plywood Under 3 4 Flooring

The hardi mfgr says the board is to be embedded in thinset mortar using 1 4 notches.

Can i put 3 8 plywood under 3 4 flooring. Pre drill pairs of 1 8 inch holes about 8 inches apart and about 3 4 inch from the edges of the boards and drive a 1 1 2 inch finish nail into each board. It can also be used under hardwood laminate and carpet but this is much less common these days because subflooring is typically smooth enough for these materials many of which are installed with a different type of underlayment or pad. The panels should be staggered every 2 feet and spaced 1 8 inch between ends. Subfloor sheets for both osb and plywood come in 4 x 8 or 4 x 12 sheets.

Alternatively screw rows of treated 1x4s to the concrete 16 in. Thicknesses for products used for subfloors are generally 23 32 inch just under 3 4 inch but thicker sheets are available where building codes call for them. Lay the 1x4s perpendicular to the direction you intend to install the floor planks. Sink the nails with a nail set.

Treated plywood to the concrete with concrete screws spaced every 16 in. The second method is to loose lay one layer of 3 4 inch plywood cut into 16 inch planks perpendicularly or diagonally to the direction of the flooring. Plywood underlayment is a thin plywood material that is most commonly used under resilient flooring materials such as vinyl and linoleum sheets and tiles. Doresoom mar 11 15 at 22 49.

I always thought mortar barely held to plywood of any kind so this kinda confuses me. The much more quantity is the cube of the thickness increase. I need to install 1 4 hardibacker over 3 4 advantech. So a 3 4 sheet of plywood will deflect 3 4x less than a 1 2 sheet of plywood and 3x less than stacked 1 2 1 4 sheets.