QUESTIONWe purchased a home about 3 years ago. After living in the home a few weeks we noticed our ceramic tile in the kitchen in a couple different places that were high traffic had a hollow sound and kind of made a crackling sound when you walked across it. It was only in two or three places and it was very minimal. My father-in-law told me most likely they did not Bond the ceramic towel correctly in those places and that is why I was making that sound. We have ignored it and moved on over the last couple years however in the last few weeks we have noticed the grout cracking and splitting in those places worse and now we have different places in the kitchen area and breakfast nook area that are starting to make the same sound hollow sound as well as the crackling sound. It is even happening in our bathroom as well instead of just the kitchen as it did before. The bathroom is located in the completely different area and it's a completely different type of ceramic tile in the bathroom. We are worried that there is an underlying issue of course but our main issue and question is can this be a foundation issue of movement that's causing this since it's happening in other places now at a later time, or was it just poor bonding from the start and some of the areas are just now being noticed?
ANSWERANSWER - Hollow sounds on a ceramic tile isn't a defect in itself, but it can be a symptom of a defect depending on the circumstances. If portions of a tile is hollow sounding or if some tiles are hollow sounding and others are not in the same area, or if a tile has become hollow sounding that wasn't hollow sounding previously, then those conditions could possibly be symptoms of a problem.
Crackling sounds when walking on tile can occur if the tile is installed over a wood subfloor that is not adequately attached. If the tile is installed over a concrete slab, then the crackling sound could be an indication that the tile is loose or unbonded to some degree.
Normally if the grout is cracked it might be an indication that the tile is loose or the substrate has too much deflection. Sometimes it might be the result of the grout having not be installed correctly when it was installed by not fully filling the grout joint with grout.
Because you say it has happened over time, it could be that there are not movement joints in the tile particularly at the perimeter of the rooms. If the tile isn't bonded as well as it should be and you don't have movement joints installed in the floor every 20 to 25 feet and at perimeters and transitions, then as the tile is subjected to stress from expanding to heat or moisture, it can cause tiles to debond.
The only way to determine for sure what the conditions that you mention mean, is to intrusively remove tiles under various conditions and look for the evidence that is causing the problems, so you can determine how best to remediate those problems.