Contrary to popular belief, neither tile nor grout (even sealed) is waterproof. In a standard shower application, a pan liner is used to block moisture. The pan liner used does not allow for tile to be applied directly to it, so a bed of mortar is used and then the tile is placed on this bed. Because the water infiltrates through this bed, it can remain saturated with moisture, especially if the mortar weep holes become clogged or the pre-slope wasn’t installed properly. With this moisture saturation, the possibility of mold and efflorescence or cosmetic staining on the tile, increases tremendously. Most new construction homes only carry a one-year warranty and unfortunately, this problem may take a little longer than that to appear. We see many houses where the homeowner is wanting to change the tile in their shower not because they want to change the size, shape, or style, but because there is a bad smell and mold growing throughout.
There is a German engineered shower system called Schluter that has a family of products that creates a “sealed” environment which is stated to be even more than water-proof, it’s vapor proof. The beauty of the system is that it doesn’t allow moisture to permeate in to the mortar bed or solid backing so there is no chance of mildew growing there. The system allows only the tile and grout to become wet when showering which is able to dry completely between uses. The system also eliminates leaks, reduces the potential for efflorescence and mold growth in the system, dramatically reduces total installation time and makes shower installation much easier because it is light-weight in nature. The product may cost a little more, but having a mold-free shower is worth every penny!