What Are Weep Holes? (Definition, Types, & Importance)

Weep holes are an intricate part of your shower drainage system, water in water out. Sounds pretty straight forward and in reality it is but a lot of things can “get in the way” of this process causing problems with drain efficiency. In this article we are going to cover the following:

Hot Mop Shower Pan Ready for Tile

What are weep holes in a shower drain?

Weep holes are a vital part of your shower drain assembly. Typically, there are three to four 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.

Why are weep holes important?

After taking a shower, there is plenty of water left behind on your shower walls, shower curtains, on the floor tile and above the grout. As the water begins to slide down the walls it will begin to collect on the perimeter edge and eventually will seep through the pores of your shower’s materials and find its way through and collect behind the tiles and into the flooring. When a shower is properly sloped and hot mopped, the excess water that is left behind will find its way through the weep holes and into the drain system.

Additionally, the weep holes allow for ventilation between materials, allowing for the material’s to “breathe” and dry sufficiently so that there is no moisture left behind between showering.

When a shower is not properly sloped, watertight, or if weep holes are blocked or not properly installed, excess water behind the shower materials can cause mold, dry rot on the sub floors, tiles to loosen, discoloration, wicking and grout to break.

Where are weep holes located in a shower?

Weep holes are located where the “stack” of the hat meets the brim (i.e. at the lowest point(s) possible). Depending on the style of drain installed, there will be three to four weep holes. The “Top Hat” part of your drain is put on right before the final “float coat” of tar is put on. Weep holes should be “cleaned out” after the hot mop has been given time to cure and before the water test is performed. This should not be ignored. It is also important to note that anyone who works on your shower after your hot mopper leaves and the drain has been tested must also clear the weep holes after their work has been performed and must test the drains once again to make sure the weep holes are working properly.

What happens when the weep holes are not working properly?

When weep holes stop working, water begins to back up and your shower floor remains damp and wet. All the mud-work under your tile absorbs the excess water causing it to rise vertically with every shower you take, this is called wicking. When enough water begins to collect and is left with nowhere to go, this can lead to many problems such as tile and grout discoloration, mold growth, and if the water wicks high enough on the vertical it can spill over the curb and/or get behind the hot mop on the wall and cause damage to walls, trim, wood subfloors, and the flooring outside of the shower. 

If your shower is showing signs of discoloration or you feel bubbling in part of your shower pan and experience tiles falling from the walls or cracking on the floor, you will want to call your local plumber to check for leaks in your plumbing or inspect the weep holes for blockage. If you have a shower or tub that was installed over 50 years ago, you will definitely want to have your shower or tub resurfaced to meet today’s building code standards.

For more information about, weep holes or to have your plumber work with us, contact us at (866) 305-4980.