I have a newly constructed bathroom that has 2x8 floor joists, 16" OC. Covered with 3/4 tongue and groove plywood. I'd like to install floor tiles and have been considering a few of options:
- tile over 1/2 cement board only
- put another layer of ply (1/2) over the 3/4 and then tile over 1/4 cement board
- put another layer of ply (1/2) over the 3/4 and then tile over 1/2 cement board
I would think that option 2 is best because it creates 1 1/4 ply for rigidity and also has the cement board for bonding and waterproof. I would screw both layers into the joists but I'm not sure if I need to put thinset under the cement board since I've heard some yes and some no. What do you think? TIA, Bob