I plan on installing 13x13 porcelain tile in my entranceway/hallway,
bathroom, and kitchen. I have a question about the subfloor and
The floor joists are 16" OC 2x10 joist (Douglas Fir) with a span of 12'
and 13'. I look good on the deflection with L/458 and L/558.
My current floor is 23/32" plywood, then 1/4" Luan, and then vinyl
flooring. I plan to tear out the vinyl flooring and Luan. I have been
told that I should not put Hardibacker on Luan since it has a greater
tendency to warp.
After I pull out the Luan I have about 1/2" to use for building the
underlayment since I will run into problems with height restrictions
namely two exterior doors that can't be cut down.
How should I build my underlayment on top of the 23/32" plywood? I
want to have a layer of hardibacker and it looks like 1/4" is actually
stronger than 1/2" ? Will 1/4" hardibacker on top of the 23/32"
plywood be enough support? Could I do this and then add blocking to
the joist under the floor to increase the support of the floor?
Thanks for the help.