Hey folks, I could really use some advice! I had a tile floor installed upstairs before my baby arrived, and while it looks fantastic, I'm now facing a pretty serious problem. I hired an unlicensed contractor (big mistake, I know) and things seemed okay at first. But just a few weeks later, the grout began cracking, some tiles sound hollow, and a few are already shifting. I've hardly stepped on it and this is happening!
After digging into some research and chatting with professionals, it seems my installer skipped a key step: he likely didn't apply thinset under the cement board. From my pictures and what I've learned, it looks like he just screwed the cement board directly onto the OSB subfloor without proper bonding. This means the cement board can move, especially on the second floor which naturally flexes more, leading to the tiles and grout issues I'm now facing.
When I jump gently in the middle of the room, the floor visibly moves. It's like building on a shaky foundation. The installer has come back three times, but his solution is just to replace tiles as they lift and regrout—not a real fix! He keeps insisting everything is fine and even offered me a $2,000 refund if it gets worse in two weeks, but I can't trust him at this point.
I'm starting to think I might have to rip everything out—cement board, thinset, tiles, the whole shebang. That's a lot to deal with, especially with a newborn at home and the need for demolition. Has anyone here faced something similar? Is there any real fix without starting over? Thanks for your help!
1 Answer
Unfortunately, tearing it all out and starting fresh is your best bet. You definitely should’ve used an uncoupling mat over the OSB, not just cement board. I had a similar experience, and my contractor used Schluter Ditra—it made such a difference!
I appreciate your input! Do you think using an uncoupling mat would have worked even without thinset under the cement board, or is it intended to replace the cement board entirely?