Why Is There a J Under My Sink?


Stop whatever you are doing right now and look at the plumbing under the sink in your home or office. If you can see a pipe, you will notice that it is in the shape of a J or a U.

OK, so you’ve likely seen this before, but have you ever wondered why it’s shaped that way?

The “U Bend,” as it was initially called, was developed in 1880. Whether it is in the shape of a U, a J, or even a P does not matter. These kinds of pipes are known as traps in the plumbing industry, and they are designed to prevent sewer gases from entering a bathroom or restroom.

The way they work is quite simple. Because of their design, they retain a small amount of water after each use of the fixture. This water creates a seal that blocks out sewer gases, preventing them from being released into the restroom. Similar traps are used in almost all plumbing fixtures, including sinks, bathtubs, toilets, showers, and floor drains.

For the most part, this simple little design has worked well for more than a century on all these kinds of fixtures except one: the floor drain. Whereas kitchen and restroom sinks, toilets, and showers are used enough to keep water in the trap, the water in floor drainpipes can and does evaporate from time to time. When this happens, offensive sewer gases can be released into the room.

Historically, this has been a serious problem for many facility managers and cleaning professionals. It often takes some time to realize that these odors are coming from the floor drain. Often a detailed cleaning is performed as a result of these complaints; however, if the real source of the problem is a floor drain, the odors will persist.

floor drain trap liquid EverPrime for smelly dried out drains

When the floor drain is finally identified as the problem, there are two relatively easy ways to address this:

·        Pour water down the drain on a set schedule—say once per week.

·        Pour a chemical known as “everprime” down the floor drain.

Everprime is biodegradable, inexpensive, and designed to withstand extreme temperatures without evaporating.

Many school districts use it. Custodians pour Everprime down floor drains to keep traps sealed during the summer months. Further, Everprime can last a year or longer without evaporating, essentially eliminating odor problems caused by evaporation from floor drains on an annual basis.

For more information on how to keep restrooms odor free, contact a Waterless Co Specialist