As a general rule, plumbing is not known for its sense of beauty and aesthetic appeal, so anytime you look under your sink and see your pipes form a big U-shaped design, you know it’s probably there for a specific purpose. But what is it, exactly? And why does it look like that?

Tilt your head to the side when you look under your sink and you’ll realize exactly why it’s called a P-trap: The shape of the pipes form a very distinct P. While it may look funny, the design actually serves a bunch of different purposes, from efficiently getting rid of waste in your sink to keeping odorous gasses from seeping back into your home.

How Does It Work?

P-traps – as they’re often called – can come in either steel or PVC form, though the metal is normally reserved for exposed plumbing since it generally looks better. Every state has their own restriction on what can and can’t be used for p-traps, so it’s important to check with your state’s codes if you plan on replacing them.

The design is simple, yet remarkably effective. Two ninety-degree joints are attached to two other straight=line pipes. One end of those straight joints is connected to the base of the sink drain, while the other is attached to an overflow pipe. Connecting the overflow pipe with the other pipe is a water seal system that allows water to flow out, but not come back towards the sink. It also serves the dual purpose of keeping noxious gases from returning back into the home. These gasses not only smell like rotten eggs but in some cases, can even be explosive or poisonous. Suffice it to say, this water seal mechanism is invaluable.

At the base of the “P” in the p-trap is a small cleanup tap that allows you to scoop out the debris that is piled up at the bottom. It’s not uncommon for these to become clogged, especially if water hasn’t been ran through the pipes in a few weeks, but removing the debris is quick and easy, even for inexperienced DIYers. Moreover, if you drop something valuable, like a wedding ring, down the sink drain, you’ll be thankful you have a p-trap there to catch it.

How To Install a P-Trap

Whether you’re replacing the p-trap under your sink or putting in a brand new one on a new home build, installing a p-trap is a simple and painless process that shouldn’t take more than half-an-hour, at most. As with most plumbing projects, make sure the water is off to the area that you’re working on, and have all the necessary parts nearby. You should be able to complete this job with minimal tools; slip joint pliers, a hacksaw (in case you need to cut the pipes to fit), lubricant, and a bucket should be all you need.

Start by placing the bucket underneath the sink drain to catch the excess water, and then unscrew and remove all of the old pipes, dumping the water from the pipe into the bucket. Attach the new tailpiece to the base of the drain, and put a T-fitting onto the bottom of the tailpiece, if necessary. Attach the trap arm to the outflow pipe, and connect the ninety-degree pipes to the trap arm. Tighten everything down with your wrench, and you’re good to go!

Replacing the p-trap is something every homeowner can do, provided there aren’t bigger issues at hand. If you feel like you need some guidance, give our team a call to ask for advice, or let us come out and give you a hand.