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Can A Washing Machine And A Sink Share One Drain? (Solved!)

Antonio Forde
Updated: March 30, 2024
5 min read

It is operationally crucial for both washing machines and sinks to have a drain. The good news is, that both appliances can share the same drain.

Find out more about how washing machines and sinks can share the same drain line.

Here’s if a Washing Machine and a Sink Can Share a Drain:

Both washing machines and sinks are crucial household cleaning appliances. The two also combine soaps and detergents in conjunction with water to clean. Whether you wash clothes or dishes, both components will always leave you with dirty soapy water that needs to be drained.

Are There Any Disadvantages When Connecting a Washing Machine and a Sink to One Vent?

Sinks and washing machines are two of the most used components or appliances in a home. Both virtually serve the same purpose. They clean. While a washing machine is only designed to launder clothing items, a sink offers much more versatility.

Although you can launder clothes in a sink, there are many more advantages when using a machine for the task.

First, it removes all the manual labor. All you need to do is simply load the washer with the right load size, throw in some washing detergent, and choose from one of the many settings.

The machine will cycle through a whole spiel or washing, rinsing, and cleaning.

The machine will also do a more cleaning thorough job than what you could do with a sink.

Washing clothing by hand in a sink is extremely inefficient and strenuous. Washing machines, on the other hand, require electrical connections.

Then there is the wear and tear on the internal components to consider.

Simply put, there is a multitude of things that should be considered when deciding how to launder your family’s clothes.

Obliviously, a washing machine and sink come with their own sets of disadvantages and advantages.

You could sit and debate the two cleaning methods all day long.

However, when all said and done most industry experts would agree, a washing machine is the easier and less time-consuming way to go.

Residential and even some commercial buildings have a room solely dedicated to laundering devices.


The basements and even the garages of some homes are plumbed for laundering appliances.

If not, you can likely plumb them yourself with a little bit of DIY know-how.

Where there is a washer there is usually a dryer.

It honestly doesn’t make sense to have one without the other unless you line in an area where you can hang the clothes outside to dry all year around.

Although a dryer doesn’t require any water, most residential models require 220 volts.

Even though the dryer doesn’t need to be plumbed for draining, it does consume space.

In fact, it consumes about as much space as a washing machine. A lot of homes have rooms specifically designed to handle laundry appliances.

Unfortunately, these rooms are usually very restricted in space.

While a sink can be an excellent addition to the room and make your laundering tasks so much easier, they are sizeable.

In most cases, it requires combining the drainage of the washing machine and sink just to be able to accommodate. This is completely okay, but if not properly piped, it could later lead to major complications. One needs to be aware of the potential disadvantages of this type of installation.

For one, the odors in the sink could travel through the pipes and get into your clean clothes.

If you aren’t using the sink for harsher smelling applications, this won’t be something you need to concern yourself with.

There is also the possibility of overloading the piping. If the washing machine and sink are draining at the same time, the drainage pipes might not be able to accommodate them.

Another thing to consider is that the washing machine uses a pump to drain water, whereas the drain uses gravity.

In certain piping configurations, it might be possible that some of the water forced from the washing machine travels back up through the sink piping and comes out into the sink basin.

Luckily, most of these disadvantages mentioned can be avoided by choosing the right installation methods.

Take the time to plumb both applications right, and you should be able to completely bypass all these potential downfalls.


How Can You Connect a Washing Machine and a Sink to One Vent?

The washing machine will probably already be in place, meaning the sink will likely be the addition.

You’ll likely find yourself tapping into the washing machine’s main drain to accommodate the sink.

The first thing you will need to do is find the main drainage line. You can follow the piping from the washer.

More than likely, it will be a 2” PVC pipe, running straight up and down behind the washer.

What you are going to want to do is find a suitable location to tap into the 2” PVC and install what’s known as a sanitary T. The 2” PVC T is referred to as a T because that’s how it’s shaped.

It allows you to connect both ends of the washing drainpipe back together while allowing for a new connection on the side.

Just remember that the sink will drain by gravity so you’ll need to install that T low enough so your sink will have proper fall the entire length it needs to travel.

Your sink may or may not have a 2” drain. If it doesn’t, you’ll have to accommodate with reducers and such.

In addition to this, industry experts would recommend installing a P-Trap or U-Trap between the sink and washing machine.

There are other in-traps available, but you’ll want to avoid these, as they don’t offer the right properties to prevent the potential of backflow of water and smells.

A P-Trap shaped like a question mark or J and a U-Trap shaped like a U are the only two suitable traps that will prevent water and smell from backflowing.

You’ll want to install the device as close to the sink as possible. It will probably work out best if you install the trap right as you come off the sink.


Best Home Secrets
Norfolk Natural Living

Written by
Antonio Forde
I'm the head-writer @ Ask The Home Geek (or, in plain English, I'm the guy writing & editing the majority of the content here). Current learning project: Korean.
Have any questions? Write us a message.
Antonio Forde
I'm the head-writer @ Ask The Home Geek (or, in plain English, I'm the guy writing & editing the majority of the content here). Current learning project: Korean.