loose tiles in bathroom

[exodus125]

Maybe someone here can shed some light on a problem I have.

When we bought our house about 5 years ago, we noticed a few of the tiles in our master bath were loose. we noticed more an more tiles get loose as time past.

A few days ago, I got home to find a row of about 8 tiles all buckled into a teepee shape right in the middle of the bathroom. I removed some of the tiles which jsut basically pulled right off and noticed some of the times had absolutely no thinset stuck. They also seemed to not ahve been pressed down hard enough for the thinset to grip it good.

My main concern is if this was caused by some kind of water damage, or is it just a poor tile instalation? All the tiles around the toilet and shower, where I would suspect a water problem to originate from have tiles around them that are ont here good, problem seems to be originating from the center of the bathroom. I suspect the one tile that had no thinset stuck to it to be the problem, but would water from walking on tiles wet after a shower cause all the tiles to lift like that? I also live in miami so the bathroom gets hot sometimes on hot days, I know heat and humidity can casue problems as well.

here are some rough sketches of the problems, the second picture shows what the floor looked liked on the loosest tile that I lifted up, the thinset looked perfect, as if the tile was not layed on it hard enough or was set on the thinset too late or something.





Any light anyone can shed would be greatly appreciated.

[jadnashua]

What you are seeing is referred to as 'tenting'. It is caused by lack of expansion joints. It is likely that the tile was set tight to the walls, and when it got warm and expanded, it had nowhere to go but up. For an experiment, take a piece of paper and lay it flat on the table. Near each end push the paper towards the opposite end slightly. You only have to move the paper a very small amount before it creates a bulge. Now, it could also be that it wasn't installed well - if they didn't use a large enough trowel and press the tile into the thinset, then you won't have good coverage. The gold standard is to achieve at least 90% coverage of thinset on the back of a floor tile, and more is better. If they spread too much thinset out before covering it with the tile, or it was too thin, or mixed too dry, or used beyond the pot life, then you may not get good adhesiion. Also, if it was walked on too soon after installation, you can have problems. If you have no expansion room, even if it is well adhered, you can get tenting, but in that case, it may crack the tile in the process rather than popping the whole thing loose. Expansion provisions are also an issue when you have a large area, or one that is unevenly heated because of large windows and sun exposure. Soft joints, or expansion joints may then be necessary in the middle of the floor as well as around the edges.

My guess is if you look, you'll find it was grouted tight to the wall, leaving it no room to expand. A good place for tiling help is www.johnbridge.com.

[exodus125]

What do expansion joints look like? I know the tiles themselves have very narrow grout lines

[exodus125]

here are some pictures

[jadnashua]

It appears that the tile is grouted tight to the walls...thus, no room to expand. There are several ways to make expansion joints: if the room is small enough, just run the tile underneath the edge, and leave a gap at the wall, hidden by the baseboard; leave grout out of a joint, and fill with a flexible (could be grout colored) caulk; install an engineered expansion joint (www.schluter.com makes a variety, as do others). In addition to sun exposure, other things can cause spot heating like heating ducts running beneath the floor.