I have a tiled bathroom floor that was poorly laid and prepared that is suffering from water damage and deterioration. The job done by the previous owner was bad enough that I intend to take it down to the joists, install a new plywood subfloor, cement board and tile. After having tiles stick to my feet or a year, I really want to prepare the substrate properly.
I’m not sure of the joist size or spacing, but some areas of the house have a bit of bounce. Would 2 layers of 3/4″ plywood provide better stiffness than the 1x boards currently in place? Should the layers of plywood be bonded with adhesive? If so, what type? What about bonding the cement board to the plywood? Durock recommends thin set or adhesive [ I will be using thin set for the tile ].
thanks – John
Replies
2 layers are stronger than one....
construction adhesive would work just fine for ply'ing the ply....then screw it down tight....
and use thinset between the ply and the backer. .....along with the screws/nails...
Jeff
Buck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
Install sister joists if you can get underneath the area or do it from above. Perhaps every other one might do the trick.
Install blocking between the joists to further strengthen the joists.
Instead of two layers of three quarter, try inch and an eight T&G plywood. Heavy as a mother, but wow, that stuff is stiff! Glue and screw that stuff down. Gap the end seams at a sixteenth.
Now check for bounciness. If it is OK, install CBU over a layer of thinset and nail away.
If it is still a tad bouncy, float an inch and a quarter mud bed over 3.5 diamond lathe.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934