Popping Noise from Tile

Q: I just had a new porcelain tile floor put down on top of a concrete subfloor. Since then I seem to have been a few popping noises in the house at random. I also have a an echo in the room from the harder floor. So, I am trying to figure out if the noise I am hearing is something other than the floor and I am noticing it more because of the echo in the room, or is there a noise coming from the floor. Have you ever heard of a popping noise from a newly placed ceramic tile floor?
Thanks.
John
A: Most tile flooring is installed using a mortar set and what likely has happened is that the mortar used set without sufficient moisture or the subfloor was not properly primed. Similar to stone installations, it could also be that the tiles were not wet slightly along the back before setting them into the mortar.
What you will want to do is find which tiles are loose by knocking on individual tiles in the noisy areas. From here you can locate which tiles were not properly set. At this point, I would contact whomever laid the floor and request them to reset the loose tiles in order to remove the noise.