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what size is bathroom sink drain pipe

What Size is Bathroom Sink Drain Pipe? How To Measure It?

Although the design of a bathroom sink and its overall dimension tend to vary, the drain holes are usually standard. 1.25 inches is the general size, but you may also find 1.5 and 1.625 inches wide holes. You must know the size of a drain hole, or else you will not be able to find out the right drain for a particular sink.

What is the standard drain size for a bathroom sink? I hope the above section served as a satisfactory answer to this frequently asked question. Please go through the rest of the write-up for other relatable information.

How big are bathroom sink drain pipes?

Remodeling a bathroom is a challenging and time-consuming endeavor. Due to the extensive plumbing work, most individuals consider seeking professional assistance. When you update the vanity, you may discover that your pipes have become outdated too. Hard water has unfortunately inflicted irreversible damages, and replacing the pipes seems the only viable option. Now you may be wondering about the right bathroom sink pipe size.

1.25 inches is considered the standard size. However, you should take your locality’s housing code into account. You may find certain areas suggest 1.5 and 1.65 inches. For the best possible results, please buy a pipe the same size as a drain hole.

What is the standard diameter for bathroom sink drain pipe?

As mentioned right above, 1.25 inches is the standard diameter for a bathroom sink drain pipe. Below are a couple of factors you should consider when selecting the pipes.

  • Compliance with House Codes

Now that you know the standard bathroom sink drain diameter, you must remember that your house may not have been constructed of the same size. Most residential properties are built as per the housing codes of the local or state government. These codes ensure the citizens’ safety and their homes’ functionality.

You must comply with the housing codes to preserve your house’s structural integrity. Doing so allows you to resell your home in the future.

  • Types of Drains

Choosing the right drain type is also necessary. You will learn about the different kinds of drain later in this write-up.

  • Functionality

You should know about bathroom sink drain dimensions if you want the drain to function seamlessly.

Plumbing issues are incredibly unpleasant. You must try installing pipes of the correct size if you do not want these issues to occur.

You will experience blockage and inadequate drainage if the pipe is unusually small. If the pipe is too big or not compatible with the rest of the fixtures, you will experience leakage that will damage the floor and other parts of the bathroom.

What are the different bathroom sink drains?

Are all bathroom sink drains the same size? No. Below are three common types of skin drain.

1. Pop-Up

Pop-up drains are quite popular. In the case of a traditional pop-up drain, the lever on the tap is used for opening and closing the drain. But in newer models, you must open and close your drain by putting pressure on your hands. Pop-up drains can be installed and removed without any hassle.

2. Grate

A grate drain is a strainer that does not have any close. This drain is generally used in the showers, but you can purchase it for the bathroom sink. Grate has impressed a larger segment of the population because it can prevent clogs. It does not allow debris to accumulate.

3. Lift and Turn

Lift and turn drains bear a close resemblance to pop-up drains. However, both of them have different functions. The lift and train drain have a grip. You have to close the drain by lifting it up, and you have to turn it to open. The drain is versatile, can be installed easily, and works well with all bathroom sinks.

How can you measure the size of bathroom sink drain?

what size drain pipe for sink
Standard sink drain pipe size

How to measure bathroom sink drain size? Many people have this query.

The drain you plan on fixing to your bathroom sink must be either the same size as the drain hole or narrower than it.

Suppose the opening in the upper portion of the bathroom sink is 1.5 inches. Then it would help if you opted for a 1.5 or 1.25 inches wide drain. This variation is crucial because the opening in the sink is generally more comprehensive.

To arrive at an informed decision, please go through the manufacturer’s recommendations.

How can you replace the pipe under the bathroom sink?

Since you know everything about bathroom sink drain hole size, it is time to learn about the ways to replace the pipe under a bathroom sink.

bathroom drain pipe sizes
Bathroom pipe size

Prepare the Workstation

Turn the water off and clean the area beneath the bathroom sink so you can replace the pipes. Set a light up. Keep a bucket under a P-trap.

Get Rid of the Couplings

Loosen the couplings and remove them on both the ends of the P-trap. Use pliers if your hands are insufficient to get rid of the couplings. Provide enough support to the assembly. Cautiously lower the assembly before pouring the waste water.

Clean Pipe Threads

Clear the pipe threads that are hanging from your sink. Scrub the threads with lukewarm, soapy water and a brush. Use a rag so that there is no residue left.

Install a P-Trap

Create a new P-trap. Insert gaskets and washers as instructed. Escalate the trap. Tighten all the couplings for securing the trap. Run the water through the drain pipes.

Collect the following materials – bucket, pliers or wrench, putty, stiff-bristled brush, paper towels, clean rag, flashlight, PVC piping, and P-trap kit.

Are all bathroom sink plugs the same?

The experts determining the bathroom sink plumbing size said drainage outlets are large because of the water moving through the bathroom every day. For bathrooms, the standard size of the plugs is 1 ½ inches. Sink plugs are also readily available in other sizes.


What is the size of PVC pipe used for bathroom sink drains?

A 1 ½ inch PVC pipe is used in bathroom sink drains. Such a pipe can handle sufficient amounts of water. The 2-inch pipe is used to whisk water out of the shower stalls and washing machines.

What Is The Standard Installation Height For A Bathroom Sink Drain?

Sink drain lines are typically installed 22-24 inches above the bathroom floor. Nevertheless, you must mark out where the drains and water lines will be located, as the installation height may vary depending on the vanity’s design and height.

Can a bathroom sink drain into a 2-inch pipe?

The 2-inch pipe is also used for draining a washing machine and shower stall. 3-inch pipes are used in toilets.

Final Thoughts

Bathroom sinks are one piece and do not include the plumbing parts. When selecting a sink, you must be aware of the drain. You have to make sure the sink has been built properly.

Thank you for reading this article hope it helped:)

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