How to Install PVC Pipe Under kitchen Sink?

Are you thinking of renovating your kitchen sink and drain? Well, did you know that you can entirely do it yourself without hiring a plumber? The task may seem difficult. But trust me, after reading through this guide, you will be ready and confident to replace your kitchen sink and drain yourself. Replacing the kitchen sink is simple, just as replacing drain pipes.

How to install PVC pipe under kitchen sink

Here are simple steps on how to install PVC pipe under kitchen sink. Normally, for the kitchen drains, PVC pipes are the best.

When replacing metal pipe under kitchen sink, you also need to keenly follow the procedure. You need a flawless connection to avoid possible leakage.  

How to install PVC pipe under kitchen sink

Some step are describes under just followed step by step

Tools and materials, you will need for installation

  • Tape measure
  • Hacksaw
  • Adjustable pliers

Steps to install PVC pipe

Whether you are replacing metal pipes or old plastic pipes, you need to follow the following simple steps.

1.Take measurements

This is the initial and very important step. You need to plan well before purchasing and installing the PVC pipes. You need to take note of the sink drain hole size as well. A small mismatch can lead to leaking.

Also, ensure that you check the size of your sink under the counter. There are different sizes of sinks, for the longer sinks, a smaller space will be left. Therefore, ensure that you take measurements using a measuring tape of the height between the drain hole and the sink drain hole above.

2.Unscrew the old pipe

Whether your sink drain is made of old metal pipe or PVC pipes, all you need is to unscrew. However, before you start unscrewing, ensure that you have the right tools to use near you. For the metal piping, you will need adjustable pliers. However, tools are not very necessary for the plastic pipes, since you can easily use your hands.

Sink drains are curved pipes, which are also known as P- traps. Ensure that you have a bucket to collect any water left in the traps to avoid spillages and damages. Once you have your bucket in place, simply turn the connections in a counterclockwise direction, and it will automatically disconnect. When disconnecting the metal pipes, sometimes it can be very hard to simply use lubricants to ease the task.  

How to install PVC pipe under the kitchen sink

3.Replace the sink drain with new PVC pipes

Once the old drain is out, the next task is to simply replace it with a new one. Now, you must have purchased your new PVC kitchen sink drain pipe, and you have it ready for replacement. Make sure that the pipes are of the same diameter as the ones you removed. Normally, kitchen drain pipes are of two different diameters, there is one measuring 1 ¼ inch and another 1 ½ inches.  

Now proceed to install your new pipes. Simply screw in the new tailpiece to the sink drain opening. Ensure that the tailpiece extends to the level where the drain pipe is located. If it is longer, make use of your hacksaw and cut it to the right length.

Now slide in the nut right to the connection at the sink drain hole and tighten. Tightening is simple, simply use your hand. Ensure that it is tight enough.

Proceed to connect the trap arm to the drain pipe. Now, you have two pipes, one hanging straight from the sink and another across from the wall. You need to connect these two pipes. This is where you need to use the P-Trap. Slide in the slide nuts to both ends before connecting. Now install the P-Trap and slide respective nuts and tighten them well.

4.Test the compression fittings

Once you are done fitting the drain well, you need to first test. To test, turn on the faucets and let the water run until the sink is full. Now let the water drain through your installed drain pipe. Bend to check if there is any leak while the water is running. If you made right tightening at the connections, there should be no water leaking.

However, if there is any leaking, spot the exact place leaking. Now use channel-lock pliers to tighten the exact nut. Gently, tighten the nut till you see that there are no more leaks. Be careful not to overtighten since plastic nuts can end up breaking if they are overtightened.

5.Clean up

That is how under sink plumbing is indeed simple. While installing your PVC drain pipes, you may have left plastic remains, or any other dirt. Ensure that you dry the area and prevent your cabinets from damage and leave the area under the sink fresh and clean. Procced to arrange your under-sink cabinet, but be careful not to knock off the newly installed pipes.

Things to note

When purchasing the new PVC drain pipes, ensure that they are of the same size as the ones you removed.

Ensure that you test first after installing the pipes to ensure that there is no leak. If there is leaking, spot the exact place, and tighten the nuts to stop the leaking.

When installing, be careful not to overtighten the nut.

Use a hacksaw to cut the tailpiece into the right length.

If you are wondering how to install double kitchen sink plumbing, simply connect the pipes from both sinks drains to the P-trap. Use the right compression fittings and securing.   

There are numerous types of PVC pipes in the market, ensure that you purchase the best quality one for it to last long. Good quality pipes are also well configurated and easier to connect and hence the low probability of leaking.

The kitchen is the place that needs to be kept clean and neat. Therefore, once you are done with the plumbing work, ensure that you leave the area clean. Dirt under the sink can cause irritating foal smell.

What is the size of the kitchen drain pipe?

PVC drain pipe under the kitchen sink is responsible for emptying wastewater to the main sewage system. These pipes connect to the main drain pipes on the wall. They are of either 1 ¼ inches diameter or 1 ½ inches diameter.

How do I tell where the water leak is coming from in my kitchen?

To find out where there is a leak, do the following:

  • Turn off all the water taps and monitor your water meter. If it keeps changing while all your taps are off, then you will know that there is a leak.
  • Check your monthly usage; if there is an unexplained rise in your monthly usage, you should check if there is any leakage.
  • Monitor your bill to tell if there is an increase.
  • Use food coloring in areas that you suspect might be leaking, if after sometimes, the food coloring changes, then you know that there is a leak.
  • Constantly check behind your kitchen cabinets to find out whether there is a leak. You can place a towel below and wait for a day. If the towel gets soaked, then obviously there is a leak either from the sink drain pipe, the sink, or the faucet.

How do I remove the tailpiece from the sink?

The tailpiece is the straight pipe attached to the sink and is connected to the P-trap. If you need to replace this pipe, you need to remove it. Unscrew the nut that connects it to the P-trap and disconnect the two. Now, pull down the pipe to break it from the sink.

Where does the kitchen water drain to?

From your kitchen sink, the wastewater drains through the drainpipe below the sink. this drain pipe connects to the main drain sewer system. Wastewater from the sewer is then collected and treated in water treatment plants. Once the water is treated, it is either released to the lake or the rivers.

Is PVC pipe durable?

Yes. PVC pipes are the most preferred pipes to be used in most plumbing works. PVC pipes are not only durable but also less costly. PVC pipes can last for many years without getting brittle. But after so many years gets weaker and end up cracking when put under pressure. Since these pipes do not corrode, unlike metal pipes, they are the safest. Safety always comes first before durability.


It is so simple how to connect pipes under the sink. You do not need the help of a plumber. This is a task that you can simply do it yourself. Whether you are replacing metal or plastic drainpipes, the procedure is the same.

All you need to do is to remove the old connection and replace it with new PVC pipes. Unlike metal pipes, these PVC drain pipes are simple to connect, you can tighten the plastic nuts using your hands. Once you are done doing the connection, simply check to ensure that there is no leak. If you any plumbing work in your kitchen, simply follow the above simple steps.

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