Hollow sound when tapping tile
We are in the middle of having 20" x 20" ceramic tile installed. Half of our 800 sqf is installed and has not been grouted yet. Installer had to take 2 days off for another commitment.
We are installing on terrazzo which has been acid washed to remove wax build up. We are using VersaBond, as it is recommended for terrazzo.
Anyway, when tapping on tiles I can hear hollow sounds in certain areas. Is this OK? Or, should installer remove those tiles and replace? He'll be back on Monday and I want to discuss with him.
Thanks for any feedback.