Hi,

I live in Florida and my home was built in 1994. Last night I was woken up by a very loud cracking noise under my floor tiles in the laundry room off the garage. None of the tiles broke,but now when I walk on them it sounds like there is loose mortar underneath them.
My question is... what caused this and is there a problem with my slab or did the mortar underneath the tile simply all bust up in this area?

Tiles will not pop by themselves. There may have been some settling of the slab over the years. The stress builds up just like in earth quake or when you stetch a rubber band. When the stress is too much things will let go. You will need to remove the loose tiles and probably a few more in all directions. Clean and scrape the floor and inspect for cracks. If you are one of those really lucky people you have some spare tiles from the original build. If not, you will have a difficult time finding a match. I have done patch jobs where I visited 5-10 tile stores before finding matching tiles and they still were not perfect. When setting the new tiles use an oil based mastic rather than thin set cement. It will allow a bit of flexing in the future because that settling problem may not be over yet.