Ceramic Tile Coming Up

[JPB]

Late one night I heard a crackling sound coming from the floor near the sliders leading out to the pool. Sounded like ants/bugs underneath the tile. Once in a while a loud crack, really a pop would come from the same area. This has also happened in a bedroom and in kitchen, but earlier this year and last year.

I have easily lifted 4 tiles from the floor. subfloor is concrete slab on grade, typical Florida. Mortar is white with good coverage.

Is the mortar failing, or is it more serious?
JPB, Florida

[Kman]

Could be a few different things.

If your slab is moving, or if there is a crack that is separating, it could be cracking the tiles, causing the loud popping you're hearing. The slab could also be heaving and settling, causing the tile to de-bond from the slab.

Do you know if there is an expansion gap around the perimeter of the floor, i.e. a gap between the tile and the framing or drywall? The framing in a wall will expand with temperature/moisture changes, basically pushing against the tile if there is no gap there, and contracting the tile installation until something gives. In minor cases, the tile simply pops loose. In major cases, tenting occurs, and the tile literally lifts off the floor in a 'tent-like' fashion.

The standard is to allow at least 1/4" of expansion room around the perimeter. If the tile is butted against or very close to the framing, problems like yours can occur.

When you pulled up the loose tiles, was there thinset on the back of the tile or on the floor, or both?

One other thing that can cause your problem is excessive heat on the floor. You mentioned you have sliding doors right there. If sunlight hits the floor for several hours a day, the tile will expand until they have nowhere to go except 'up'.

[JPB]

Popping Tile

House built 1993. Tile installed in April 2006. I noticed many soft spots in the earth around house. I thought it might be moles. There is a small chance water is getting under house from bad pool piping or sprinkler piping, but that would not explain the small area in the corner of bedroom. Therefore, I will dig around the perimeter of foundation and see what I find. Thanks for the help. John