If you take a look into your kitchen sink cabinet, you’ll notice a system of pipes attached to your kitchen sink drain. At first glance, it can seem complex to understand, but in reality, it is a simple system. This past month I installed a new kitchen sink. As I installed my sink, I wondered, why not install my kitchen sink plumbing as well? My pipes were old, and since my kitchen was already a mess, I said, why not?

The kitchen sink plumbing is a system of various connections that you need to install correctly. The biggest challenge is ensuring that you align all your connections properly, especially the P-trap. I would suggest observing your existing kitchen sink plumbing before you tear it down and install your new one.

To gain easy access to pipes, I removed my sink cabinet doors and proceeded to turn off my main water supply valves. If you have never worked on your plumbing before, this project could seem challenging. But, from my experience, I can tell you that not only was it an easy, do-it-yourself task that saved me from calling in a plumber, assembling the plumbing myself also made me knowledgeable about how to fix future leaks and clogs.

After you finish reading our instructions in just 14 straightforward steps, you will be able to install kitchen sink plumbing in your own home!

Average Cost To Install Kitchen Sink Plumbing

The cost to install your kitchen sink plumbing will depend on the number of parts that you choose to install. If you’re replacing everything from your sink drain to the trap-arm, this project will cost between $100-$300.

Time Required

If you have never worked with kitchen sink plumbing before, it will take you between 2-4 hours to install. The key to success for this project is to be patient and complete each step properly to avoid leaks and loose connections in the future.

Tools & Materials

• Screwdriver
• Hacksaw
• Adjustable wrench
• Plastic Drain Pipes

How to Install Kitchen Sink Plumbing

1. The first step is to install your kitchen sink drain. The sink drain will be the primary point of drainage and needs to be properly installed. Here’s our guide about how to install a kitchen sink drain.
2. Once the drain has been installed, you can work to fit your kitchen sink assembly. Tip: Metal nuts will be used on metal parts of your assembly, and plastic nuts will be used on the plastic connections such as the drainpipe and P-trap.
3. You’ll have to attach a small plastic tailpiece onto your metal sink drain basket. This tailpiece will serve as a connection between the sink drain and your drain pipe.
4. Drop the plastic tailpiece through the metal slip-nut. Additionally, place a tailpiece washer on the top opening of the tailpiece. The threading on the washer makes it extremely easy to attach.
5. Screw the metal nut onto the drain basket by hand. Use a wrench to tighten it a little.
6. Furthermore, connect the tailpiece to the drainpipe using a plastic slip-nut.
7. Thread the slip nut onto the tailpiece and hold it in place. Also, place a nylon washer onto the end of the tailpiece.

We suggest using a nylon washer as they are more durable than their plastic counterparts. Also, they are threaded at the bottom, which makes them fit perfectly into the drain pipe and create a watertight seal.

8. Once the washer and slip-nut are in place, attach the drainpipe opening and tighten the nut by hand.
9. Next, attach your plastic trap to the main drain pipe using a washer and slip-nut. The drain’s stub-out is threaded, onto which you can first fit the washer and then twist the slip-nut by hand to attach the trap arm.

TIP: Remember to keep the bevel side of the washer facing the threaded drain stub-out.

10. We suggest attaching the connections to the main drain pipe before you work on the P-trap. This is because in case your P-trap does not perfectly align with the wall outlet, you will have to attach a plastic extensions pipe that will connect to the drainpipe coming from your sink drain.
11. Hold the P-trap in place to measure whether it connects appropriately with your drainpipe and the trap arm. In case it doesn’t, follow these steps:

• Take your plastic pipe and measure the appropriate size needed.
• Using a marker, mark where you need to trip the pipe.
• Furthermore, use a hacksaw to cut the pipe.

12. Attach your extension pipe using a slip-nut and a washer.
13. Once your extension pipe is in place, proceed to attach your P-trap.
14. Attach the P-trap to the extension pipe on one end and the trap arm to the other using slip nuts and washers.

Check each of the connection by hand to ensure that they are tight. Once satisfied, open your main water valves and let water flow through the pipes for a few minutes.

Frequently Asked Questions: How to Install Kitchen Sink Plumbing

Do I need to attach washers at all connections?

It is advised to use washers at connections as they help create a watertight seal to prevent leaks and add durability.