I havea tiled shower that does not completely drain due to improper sloping. A 12" section keeps about a 1/4" of water. The shower is on a concrete slab. The water collects in the middle of the floor with the drain on the left side of the shower and the shower head on the right. Do I need to worry about ant potential damage over time? Mold? Could glazing the tile fix this problem since it us a minimal amount of water?