I laid some ceramic tile about 6 years ago in a family room. There are some tile that sound hallow, Like they did not set in the adhesive securely. Nothing else is wrong with the tile, but it does sound hallow when you walk on it. I laid the tile on a concrete slab. How would you go about fixing this? I thought of drilling a small hole in the center of the tile and spraying some liquid insulation (that you put around windows) and grouting the hole closed with some grout the same color as the tile.
Don't do the insulation thing, it will crack the tile. It is not unusual for that to happen. To fix it take a chisel and dig out the grout around the edges. Then very gently with the bevel on the chisel toward the floor try to get it under the edge of the tile and work around the edges to pry the tile up. The chances that you will break the tile are about 85%, or 95 % you will damage the surrounding tiles so leave the thing alone until or if it breaks on it's own.
you need to remove the grout around each tile to be removed and with a chisel or punch gently break the tile to be removed and replace with a new one then re grout.
The best way is to remove the affected tiles remove the adhesive then reset the tiles
Remove the grout from around the tiles in question. Using a stiff scraper, gently work it under the tile. Remove tile and clean both the floor area and back of tile. Vacuum and thin-set both floor and back of tile. reset and grout after about 12 hours curing time.
By coincidence I had the same situation once. No...! You don't want to do it that way. First the tiles can crack, it's not going to seal and the hole is going to be ugly. The only pain full solution here and it's not very easy is to cut the grout with a thin masonry bit and a drill moving along while you cut'em and very carefull so you don't crack the tiles and lift every loosen tile. Clean the old grout from every tile after removed and then clean the old cement from the floor with a spatula very smooth and then with a sanding grinder and a masonry disk out doors. Now you must use fresh tile cement to re install the tiles again. Good luck...!
