Tile Advice - "Pops" and "Snaps" Coming From Under Tile

[Hokiedale]

Hello Everyone,

This is Dale from NC. I have asked the advice of this forum here and am greatly appreciative of the advice that I have received so far. All of my questions in the past have dealt with professional (professionals sponsored by the local tile house) installs of ceramic tile. This is no different.

I have a kitchen floor that was installed about two years ago. I did not physically see the prep for the floor, but when I asked about the installation, I was told that thinset was put over the OSB, cement board was put over this and screwed, and the tile was layed over this (of course in a bed of thinset). I have at least 4 places (this is how many I have identified to date) that, when I step over a certain spot on the tile, it pops or snaps. The spot that snaps within the individual tile is always the same and the "pop" is sometimes loud, but most of the time you can get repeated softer pops by stepping on and off of the tile. Three of the tiles are in the interior of the room and one of the tile is on the perimeter. Only the tile on the perimeter shows any sign of grout crack. We have had a high temp, dry summer here (but high humidity), and these pops were not noticed until about three weeks ago (beginning of Aug timeframe). I cannot visibly see any deflection in the tile (not that it is not there). The house was built in 2004, so everything should be code with respect to joist.

My questions are:

(1) Is this common? I searched this board and found a few threads but most of these dealt with inproper installation (my tile guy did not use pre-mix
thinset and the floors appear to have been prep properly)
(2) Is this where adequate thinset coverage was not acheived under the tile?
(3) I believe that the tile is porcelain (12 x 12). Can I just take up the concerned tile and reset with a new tile ... I realize that the grout may not match (I still do, however, have some of the original grout left over), but these "pops" are quite annoying. One of them is in a spot that almost cannot be avoided (and this spot has the loudest pop)

I, again, appreciate any advice.

[Rd Tile]

Tap on the ones that pop, do they sound hollow?

Is the perimeter of the room grouted or caulked or left open and covered with baseboard?

[jadnashua]

Note, grout has a shelf-life...about the only thing you should use the old stuff for is to get the brand and color - get some new stuff. If you're lucky, that color is still available, but don't expect it to be a perfect match since there are differences from batch to batch of the stuff when you buy it at the same time - same as wallpaper, carpet, etc.

[Davestone]

I wouldn't be surpised if the osb is inadequate(too thin) to apply a tile job over if the trusses are 24" on center.

[Hokiedale]

Thanks for the quick replies.

I measure the joist centerlines and they appear to be pretty consistent at 19 1/2".

I can't say that when I tap on the tile that I hear a hollow sound ... maybe on the one perimeter one that joins up to the carpet. The remaining perimeter is left open and covered gaps with baseboard.

Thanks for any additional input.

[Davy]

It's movement of course, either the tile or the wood under it. If you have an a/c register in the floor, you can take it out and look at the plywood used.