Shower pan/tile weep holes

Why do these exist? Are they supposed to be filled in some situations? Recently I had a client’s builder say this was the reason for some extensive wall damage around the shower. The holes had been filled in this case. While I am happy he is fixing the problem for her, I kinda doubt his opinion and think there may be other undiscovered problems.

I certainly understand the function of a weephole. I question however why you would ever EVER want water or moisture of any kind behind the tile in a shower, and be content to just allow it to drain out without correcting the problem that allows it in. Around here they are generally using greenrock under tile (if you are lucky.) As far as I know that is going to soak up water, not let it drain to a weephole.

Opinions? Concensus? Should these weepholes be filled or open? Are there exceptions?


I’ve seen photos and descriptions of several custom showers and tubs where the weepholes were blocked. Extensive damage is common (black and fuzzy). The weepholes are intended to drain moisture that penetrates grout or nearly invisible cracks and also from condensation between materials that are influenced by different temperature zones (outside wall) or porosities.

The weepholes are essential to draining or relieving moisture, especially the weepholes in the drain of shower pans or tubs that are tiled over concrete, wood, etc.

Even if they weren’t essential in a particular case, if someone felt the weepholes needed blocked, they would be using the wrong product and ingnoring the manufactuer’s intended application. Manufacturers make weepholes for a reason other than to be blocked.

As an aside, I believe greenboard is no longer listed for wet locations and all new construction should be using Durarock or some other cement board.