Re: Help! Tile floor question ASAP!
Ideally ..... Embed the cement board in latex-modified thin-set mortar.
The main reason for using thin-set between the cement board and the subfloor isn’t only for bonding ...... for even, void-free cement board support throughout the floor. Embed the cement board and screw it to the underlayment with special 1-1/4 in. cement board screws spaced every 4 in.
This would be the method I would recommend for a good clean plywood subfloor.
Hope this helps.
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