I was only going to remove and replace some grout on my shower floor when I accidently dropped a small tool on the floor. The tile made a hollow sound. I removed the tile, and the thinset came up with the tile. Under the thinset was sand. I've read that deck mud is used, but should it be dry? It is almost like play sand. Is this going to cause a problem in the long run, or should I just reapply thinset and replace the tiles? The home is only 5 years old. Also there is about 1"-2" loose sand and then it is hard. IAny help would be appreciated.