I am in process of remodeling my kitchen and am removing the existing 3/4″ oak strip floor and replacing with 5/8″ thick limestone tiles, random sizes (8×8, 8×16, 16×16, 16×24).
The existing floor construction is 1/2″ ply nailed on 2×10 fir joists, 16″ O.C. (No glue.)Joist span is 14′. The “Deflectolator” at http://www.johnbridge.com/vbulletin/deflecto.pl gives this floor an L/380 rating…not nearly enough for stone. I intend to add a beam and posts beneath to reduce the span to 10′-4″ and increase the rating to approximately L/800, which meets the L/720 minimum for stone flooring.
The 1/2″ plywood subfloor is clearly inadequate, so what is recommended for the subfloor preparation prior to this stone installation? Can I simply screw the existing 1/2″ ply to the joists, glue and screw 3/4″ T&G ply on top, then add 1/4″ cement board?
Thanks in advance for your expert advice.
Replies
Keep in mind I don't know much about tile, but from reading quite a bit off john bridge's site, your plan to put 3/4 TG plywood would work fine. That would get you 1 1/4 and your backer, which should work.