Customer has a very small bathroom with plywood subfloor, they’ve laid some carpet on it but she’s gone out and bought some 12×12 1/4″ thick tiles for the floor. I dunno, I think it’d be OK to put it down with some mastic or perhaps thinset… but somehow I’m a little leery of either. Perhaps put down some 1/4″ cement board first and thinset the tile onto that? I don’t imagine there’s gonna be a huge amount of water on the floor, they’ve been getting by for over a year with carpet.
My goal is to do it “right”, whatever that means in this case.
I think we could stand another 1/4″ under the tile and not overshoot the carpet in the adjacent room.
Replies
I have done a few tile installs like this. First, screw the floor down every 6 inches into the joists. Then anothe layer of 3/8 ply glued with pl premium, screwed again every 6 inches into the floor joists and a row between the joists. Tile with Flex bond thin set mortar, clean and grout the next day. The 3/8 ply adds stiffness and your tile will be a good height to match the carpet and right on if the want you back to install 3/4 inch hardwood.
Have a good day
Cliffy
It all depends on whether the result will be stiff enough to not flex and crack the tile.
The all-out approach would be to pull the subfloor, glue and nail cleats to the sides of the joists 1 1/2" down, and glue and nail two rips of 3/4" ply on the cleats between the joists. That gets you a very stiff surface at the level of the top of the joists. A lot of work, though.
From there, you have plenty of room for a water barrier, cement board, whatever you want....
-- J.S.
About 15 years ago, when we redid our upstairs bath (from sheet vinyl) the guy at the store (knowledgeable -- not an HD type) had us put down a layer of expanded steel, then thinset over that. This was over 1/2" subfloor and 1/2" underlayment. It added maybe 3/8" thickness. Then more thinset and the tile. (I did put a box of deck screws into the floor first.)
Now some of the concrete board products are probably a better choice, though there are potentially important differences (that I can't explain) between the various ones.
happy?