man working on sink pipes

The sink trap is the part of the drain pipe found underneath the sinks in your home, which is also called a drain trap or P-trap. Plumbing and building codes require a P-trap under the sink as part of the drain line.

However, sink traps can wear out long before other drain lines and will need to be replaced. Sometimes the connections start to leak and can no longer be securely tightened. In addition, metal sink traps can corrode and rust, so they eventually develop leaks. 

Does your sink trap need to be replaced? Have other plumbing problems? Call the plumbing experts at Larkin Plumbing in Las Vegas to schedule service today.

What does a sink P-trap do?

A sink P-trap serves several useful purposes. For starters, while it might seem more efficient just to plumb the drain line without the dip, there is an actual reason for this dip. The dip in the sink trap retains a small amount of water. This water prevents gasses from sewer and drain lines from coming up through the sink drains and into your home.

Another valuable function of a P-trap is to provide easy access when you need to recover small objects that accidentally got dropped down the drain, such as a wedding ring, an earring, or a bracelet. Without the P-trap, the item would be washed away and end up in your septic tank or city sewer system. 

Lastly, the P-trap sink drain provides easy access when clearing drain clogs. While some clogs form in the drain trap, others can occur further down the drain line. By removing the P-trap, you have easier access to clean the drain pipes and remove the clog. 

Is it easy to replace a sink trap?

Replacing a sink trap is relatively easy if you understand basic plumbing principles and have the right tools and equipment. In addition, the type of sink trap determines the level of difficulty. For example, PVC P-trap is the easiest to change because you loosen the connections to remove the drain trap.

Are all sink traps the same size?

No, sink traps come in different types and sizes based on the drain line size and sink. For instance, kitchen sink drains usually use two-inch P-traps, while bathroom sinks use one-and-one-half-inch P-traps. So, it is essential to know what size you need

Related: 5 Types of Kitchen Sinks For Your Home

How to Replace a Sink Trap

Step 1: Gather Your Materials

Before you get started, you will need the right size P-trap replacement kit, which should include slip washers, and “nut” connectors. You will also need a pair of adjustable plumbing pliers, pipe sealant, rags, and a bucket. 

Step 2: Remove the Old P-trap

Place the bucket under the P-trap. Loosen and unscrew the “nut” connectors on the P-trap. Gently pull the drain trap apart from the connecting drain pipes. Some water may leak out, so have rags ready to wipe up any water that does not go into the bucket. Next, place the P-trap in the bucket. 

Step 3: Install the New Drain Trap

Remove the bucket and wipe up any excess water with a rag. Slide the “nut” connectors onto the pipe, then slide the slip washers on. Next, apply pipe sealant directly below the slip washers. Finally, slide the pipe ends into the existing drain pipes. 

Then tighten the “nut” connectors to the existing pipes until secure by hand. Lastly, use the pliers to fully tighten the connectors but avoid over-tightening. 

Step 4: Check for Leaks

Put the bucket back under the sink. Put a sink stopper in the sink and turn the faucet on. Fill about halfway full with water. Remove the stopper and check for leaks as the water drains out of the sink. If there are any leaks, ensure the connectors are tightened fully and recheck for leaks. 

Benefits of Hiring a Local Plumber

Changing a drain trap is usually easy to do. However, metal drain traps can be more difficult to change because they have metal connectors that can corrode and become challenging to loosen and remove. 

Furthermore, when all the drain pipes are metal, and you are replacing it due to corrosion, the other pipes could also break while changing the P-trap if they are also corroded. So, it can be better to hire a plumber when dealing with metal drain pipes.

Even when changing PVC P-traps, there can be difficulties. For instance, if the “nut” connectors were cross-threaded when installed, it can be difficult to loosen them up. Sometimes, “pipe gunk” can harden between the connected sections, making removing the drain trap difficult. 

Additionally, cross-threading and leaks can occur if you do not align the “nut” connectors precisely. By hiring a local plumber, you can avoid these issues.  

Other benefits you gain when you hire a local plumber to change your sink P-trap include:

  • You do not need any plumbing tools or supplies. Your plumber will have everything necessary to change the drain trap. 
  • You do not have to worry about determining what size sink trap you need. Your plumber will have multiple sizes of drain traps in their service van. So, they will have the size you need. 
  • Your plumber does a detailed inspection of your drain lines. In addition to changing the P-trap, your plumber will check your drain lines to ensure they are clean and there are no other plumbing issues.
  • No mess to clean up. Your plumber will ensure they clean up after themself when they are done replacing the drain trap. 
  • Your plumber has other plumbing pipes in case more than the drain trap needs replacing. Sometimes, replacing other pipes connected to the P-trap is necessary if they are corroded or leaking

Final Thoughts on Replacing a Drain Trap

Replacing a sink drain trap is not too difficult if you have the right plumbing supplies and tools to do the job. However, if you lack the skills, are dealing with corroded drain lines, or simply want the convenience of having a professional replace the drain trap, then it is better to hire a local plumber. 


When you need to replace a sink trap in Las Vegas, you can count on Larkin Plumbing. Request a free quote or schedule service today


Stickley, A. (2022). Understanding the Plumbing of the Bathroom Sink.

Wentz, G. (2022). Kitchen Ideas: A Better Sink Drain.

Bhandakkar, K. What Is a Plumbing Trap and 14 Types of Plumbing Traps.