What is the Purpose of a P-Trap?

Have you ever glanced under your sink only to see many pipes? You realize water needs to drain from the sink; nevertheless, is this entire plumbing pipe essential?

Yes! Beyond just water, these pipes help keep your home smelling clean.

What is a P-Trap?

Even if you aren’t into plumbing, you may have seen the U-shaped piece under your bathroom or kitchen sink. This plumbing tool, P-trap, is an essential part of your home’s plumbing system.  It can be made from PVC pipe or steel; the latter is always used for exposed plumbing as it is more attractive. 

Also, PVC P-traps last longer, are made of white plastic and are easy to install by hand without any tools. Plastic P-traps contain nylon connectors that can be fastened by hand with the twist of the plastic nut. This makes it easier for most homeowners to fix it themselves. 

A P-trap that is not adequately serviced or installed can lead to many problems for the sink it is fixed to and other systemic issues; therefore, it is always essential to hire professional plumbers for P-trap work.   

What is the Purpose of a P-Trap?

You may want to ask why the P-trap part of my plumbing is essential. Well, there are three significant reasons:

  • The P-trap holds solids that can clog the sewer line or the drain.
  • The P-trap prevents sewer gases from returning into your home through the drain line.
  • Plumbing codes need a P-trap to be fixed anywhere an open drain line removes wastewater into a drain-waste-vent system.

How does P-trap work?

A P-trap got its name because it joins two 90-degree joints with a horizontal overspill pipe and allows the whole unit to be in the shape of the letter “P.” One of the joints (90 degrees) is fixed to the exits of the sink's drain and then connects to another, which contains a water sealant system.  

P-traps in a bathroom or kitchen sink will work the same way; however, they are not of the exact sizes. Kitchen sink P-traps are usually 1½ inches in diameter, and bathroom sink P-traps are often 1¼ inches in diameter. 

The way P-trap safeguards is as follows: there is a water sealant in the curve of the trap that prevents sewer gases from returning into your drain while letting wastewater pass simultaneously; solids will stay in the trap so they can weaken. 

Anytime the trap is used, new water flows into the P-trap, dislodging out any remnants that may be in the trap part of the pipe. But, over time, a P-trap can wear out just like any other part of your plumbing system, and replacement may be essential.  

Does a P-Trap Need a Venting?

Every sink requires a sink vent. A plumbing fixture, such as a sink, cannot work correctly without a sink vent. When a drain pipe empties water, it creates a backward pressure in the sink drain; the back pressure will drag the water out of the P-trap of the sink that’s evacuating, and sewer gases can enter your home if a sink vent is not attached. 

There are many different ways to install a sink vent in your home, even if you want to fix a sink vent on an existing sink. A sink requires a vent because the pressure put on the drainpipe when water drains down the drainpipe needs to balance.

In older cabins, commercial buildings, homes, and even in inappropriate vented additions, one can sometimes hear a “glug, “glug” sound when you use the drain. This usually is the noise of sewer gas and air being pushed or pulled through a P-trap. Without the right help, this will later cause the water seal to slow down, stopping the P-trap from protecting your home or building from sewer gases.

However, sewer gas smells like a P-trap that has lost its water seal. P-traps tend to dry out if not used for a very long time, which may cause leakage or if something has removed the water in the trap. Waste materials such as fibers or a clump of hair can easily break the water seal. In some areas, it can take 3 to 5 months without use for water within the P-trap to drain out and let the sewer gases flow inside. 

Tracking down the sewer smell

Several factors can cause sewer gas smells, and getting rid of them requires a bit of logical detective work. Whether the smell comes from an unused P-trap or an unclosed cleanout that has been covered by drywall, dealing with the problem will require patience, precision, and the experience of a professional plumber as well as a DIY home.

How is P-Trap Install?

One of the best parts of the P-trap is that it is cheap and easy to install. Just be sure to connect the PVC pipe correctly to ensure tight seals and prevent leaks. However, you can ask a professional plumber to help you decide whether the P-trap is permitted in the plumbing section where you wish to fix it; nevertheless, there are two rules of thumb to guide you on the right aspect of the code.

  1. It is not advisable to install more than three utility appliances onto one P-trap. This means that if you have plenty of sinks in a washroom, for example, only three sinks can be installed on a line using one P-trap.
  2. Any P-trap attached to a plumbing line that will occasionally be used should contain a trap primer applied. A trap primer assists in keeping the seal in a position that will stop the flow of sewer gas. Regularly used P-traps or ones in arid weather, the risk of having the water vaporize within that is essential for the trap to work.

However, if you are considering upgrading your bathroom or kitchen plumbing or have horrible smells coming from your pipes, remember to get a P-trap.   

Have a pipe burst or need a repair, schedule a booking today!