How To Install A P-Trap On A Double Sink – A Step-By-Step Guide

Are you planning to install a double sink in your bathroom or kitchen? If so, you’ll need to know how to properly install the P-trap.

The P-trap is an essential component of any sink’s plumbing system, as it prevents sewer gases from entering your home and helps keep your sink drain flowing smoothly.

In this article, we’ll guide you through the process of installing a P-trap on a double sink, step by step. Whether you’re a seasoned DIYer or a beginner, our easy-to-follow instructions will help you get the job done right.

So, let’s dive in and learn how to install a P-trap on a double sink!

How To Install P-trap On Double Sink

Step 1: Connect the Drain Tailpieces

The first step in installing a P-trap on a double sink is to connect the drain tailpieces. Make sure that the drain tailpieces are at an equal height for both basins. Use a PVC cutter or a hacksaw to mark and cut accordingly. Then, fit the drain tailpieces to the basket strainers with compression nuts. Be careful not to tighten them too much, as excessive pressure could result in damage.

Step 2: Install the Sink P-trap

To install the sink P-trap, measure and cut the wall tube to the required length. Insert the wall tube into the connector, ensuring that you use a slip joint washer to create a seal. Tighten the seal using the appropriately sized nut that comes with the kit. Place a nut and washer on the tailpiece connected to the fixture drain. Join the j-bend to the tailpiece, securing the seal with another washer and tightening it using the included nut. The tubular design of the P-trap makes it easy to snake the drain or disconnect it for cleaning out debris.

Step 3: Install the Shower P-trap

If your double sink has a shower, you’ll need to install a shower P-trap as well. Measure and cut the drain line, then install the fitting to the drain using one of four types of connections: threaded, solvent, or rubber caulking. Once you determine which type of connection to use, install the drain and tighten the nut. Use PVC or ABS fittings for any directional changes needed. Locate the P-trap under the outlet of the shower. Dry-fit the drain pipe, P-trap, and fittings to ensure correct placement. Disassemble these components and solvent weld them together.

Step 4: Test Your Installation

Once you’ve installed both P-traps, it’s time to test your installation. Turn on both sinks and let them run for a few minutes. Check for any leaks or unusual sounds coming from your plumbing system. If everything looks good, congratulations! You’ve successfully installed P-traps on your double sink.

Remove The Old Drain Pipes

Before you can install the new P-trap on your double sink, you need to remove the old drain pipes. This process involves unscrewing the nuts that connect the P-trap assembly to the drain extension and waste line using adjustable pliers. If the nuts are stuck due to age or rust, use a spray lubricant to loosen them.

If you’re working with a double sink, you’ll need to loosen the nuts on both tailpieces. Once you’ve removed the nuts, gently pull the old drain pipes away from the sink. Be careful not to damage any other components during this process.

It’s important to note that in some cases, the trap arm may be longer than your sink configuration. If this is the case, you can cut the straight section of the trap arm to match the size of your sink. Use a PVC cutter or hacksaw to make the cut. Some kits may also come with trap arms of various sizes to make installation easier.

Removing the old drain pipes can be a messy and time-consuming process, but it’s necessary for a successful P-trap installation. Make sure to dispose of any old pipes properly and clean up any debris left behind before moving on to the next step.

Connect The P-trap To The Drain Pipes

After connecting the drain tailpieces and installing the sink and shower P-traps, the final step is to connect the P-trap to the drain pipes. To do this, slide one slip nut, thread-side down, over the sink tailpiece, then slide on a slip nut washer, tapered-side down. Insert the P-trap into the tailpiece and tighten the slip nut by hand. Use a pair of pliers to tighten it further, but be careful not to overtighten it as this could damage the seal.

Next, slide another slip nut washer, tapered-side up, onto the wall tube. Insert the wall tube into the P-trap and tighten the slip nut by hand. Again, use pliers to tighten it further without overtightening it. Finally, check all connections for leaks and make sure that everything is securely fastened.

By following these simple steps, you can install P-traps on your double sink and ensure that your plumbing system is functioning properly. Remember to take your time and double-check all connections to avoid any potential issues down the line.

Test The Sink For Proper Drainage

After installing the P-trap on your double sink, it’s important to test the sink for proper drainage. To do this, turn on both faucets and let the water run for a few minutes. Observe the water flow and make sure that it’s draining properly. If you notice that the water is draining slowly or not at all, there may be a blockage in the drainpipe or P-trap.

To check for blockages, turn off the faucets and place a bucket under the P-trap. Loosen the slip nut connectors and remove the P-trap from the drainpipe. Check for any debris or blockages in the P-trap and remove them if necessary. Once you’ve cleared any blockages, reattach the P-trap and test the sink again.

If you’re still experiencing drainage issues, there may be a problem with the slope of the trap arm or the placement of the drain outlet in the wall. In this case, it’s best to consult a professional plumber to ensure that your double sink is installed properly and functioning correctly.

Troubleshooting Tips For Common Issues

Despite following the installation steps carefully, you might still encounter some issues after installing P-traps on your double sink. Here are some common problems and how to troubleshoot them:

1. Slow Drainage: If your sink is draining slowly, it could be due to a clog in the P-trap. You can remove the trap and clean it out with a wire hanger or a plumbing snake. If that doesn’t work, you may need to call a professional plumber.

2. Leaks: Leaks can occur if the P-trap is not tightened enough or if there is damage to the trap or its components. Check all connections and tighten them as needed. If there is damage, you may need to replace the damaged part.

3. Foul Odors: Foul odors coming from your sink could be due to a dry P-trap. The water in the trap creates a seal that prevents sewer gases from entering your home. If the trap is dry, pour some water down the drain to refill it.

4. Double Trapping: Double trapping can occur if there is an air vent issue between the two traps, causing drainage issues. Make sure to install an air vent between the two traps that vents above the drain inlet to prevent this issue.

By following these troubleshooting tips, you should be able to resolve any common issues that may arise after installing P-traps on your double sink. Remember to always exercise caution when working with plumbing and seek professional help if needed.