Waterproofing your showers sounds ridiculous at first…why check if something designed to withstand water is waterproof. The answer is simple; because of human error. While water might not be flowing out of your shower, that doesn’t mean that it’s fully waterproof. The issue of improper waterproofing typically occurs with tile showers.
Moisture forming in the shower needs a place to go, so they are built with a weephole. A weephole is a spot without any caulking. This spot allows moisture to drain back into the shower before exiting and causing damage outside. Whether it’s done by the installer or the homeowner, the weephole commonly ends up filled with caulking. The misconception is that a gap in caulking is what causes water damage – therefore people think they are supposed to fill it in. By filling in the gaps (weepholes) you are preventing your shower from being waterproof.
Without a weephole, moisture will travel outside the shower, behind the baseboard trim and onto the floor. Even if your bathroom floor is tile, it won’t prevent your floors from being affected by the moisture buildup. Tile is more water resistant than other flooring, however it is not waterproof – damage can still occur.
Warning signs that your shower/tub is not waterproof (doesn’t have a weephole) are, mold at the wall-to-floor transition, efflorescence in the floor tile grout joints, and tiles falling off the wall. Moisture trapped in dark places breeds mold, which can cause health risks and can attract bugs like termites and carpenter ants which can cause even more damage to the bathroom. The spread of mold can be bad enough to cause the shower and floor to need replacing.
Remodeling your bathroom should be your decision, not forced upon you due to water damage/mold. Sealing the grout and leaving the weephole open is the best way to prevent the spread of mold in the bathroom.