What Are Weep Holes in a Shower Drain?

The structural elements in your home contain some functional features you may not be aware of until something goes wrong with one of them. Unless your shower begins to leak or harbor a musty or moldy odor, you may never hear of the weep holes in the shower drain, which could be a major part of your problem.

Weep holes are a vital part of your shower drain assembly. Typically, there are three such holes in the upper portion of the drain assembly, spaced evenly around the drain. The weep holes are small holes that connect to the main drain, allowing water that enters them to feed into the drainpipe. If your shower drain is all one piece with the shower pan, you may also have weep holes in the pan itself.

Weep holes are especially important in showers with tiled floors. Over time, water from the shower can work its way through tile and grout to the shower pan beneath. Without weep holes, that water has no way to access the drainpipe. The water builds up beneath the tile until it is forced into the walls surrounding the shower. This leads to leaks and water damage in the walls. If the shower is on the second floor, you also could experience water damage in your first floor's ceiling. Weep holes give the water an outlet, funneling it into the drainpipe.

Issues arise with weep holes in shower drains when they get blocked. If the water supply in your area contains high concentrations of lime and calcium, the minerals can build up in the weep holes until they are sealed. More commonly, the weep holes are inadvertently sealed with mortar when a new tile floor is laid in the shower. Because water damage won't appear immediately, you may not know there's a problem until long after the installation is finished.

If you're planning to put a new tiled floor in your shower, take precautions to protect the weep holes of your shower drain. Cover them with bits of broken tile or gravel. This prevents the mortar used to hold the tiles in place from getting into the weep holes and sealing them shut. If the weep holes are blocked, you'll need to pull up tiles to access them and scrape them clean.