How To Vent A Washing Machine Drain Pipe In 7 Steps?

Vents work as a medium for making sure that your washing machine drain pipe doesn’t overflow. They release the unnecessary pressure built up there.

Omitting the vents would be a recipe for disaster, as the drain pipe would overflow at some point due to excess pressure. But once this problem is solved, you won’t be facing any problems with the drain pipe unless there’s a leak.

So, why not check out our step by step guide on how to vent a washing machine drain pipe?

You’ll need to follow the 7 steps mentioned in the guide to get the job done. You start off by measuring the distances. Then you’ll set the elbow joints, cut the metal sheets, and join the ducts. Lastly, you’ll lay a pipe strap and drill things into place.

how to vent a washing machine drain pipe

That was a small peek into the whole process. So, after checking out our essentials for this job, let’s jump right into the process.

Get These Essentials

You’ll need this to measure everything and determine what you need.

Elbow Joints

These joints will connect the washing machine drain pipe to the duct and eventually to the outside vent.

Metal Ducts

These will make the structure of the whole vent system that we’re trying to make here.

Metal Foil Tape

You’ll need this to tape the elbow joints to the metal ducts and set the things into the system.

Screwdriver Set

These will help you screw in different parts of the structure of the vent system here.

U-shaped Pipe Strap

This will be used to set the duct into place after you’re done putting everything into place.

Now that you know about the things that you might need, let’s move to the steps of the process.

How To Vent A Washing Machine Drain Pipe?

Here are the steps you can follow to finally vent your washing machine drain pipe. You’ll have to put a good amount of focus.

So, here goes:

Step 1 of 7: Measure the Differences

Start off by preparing for the job. Take proper measurements of everything and make sure you know what to get.

Measure the distance between the washing machine drain pipe and the vent hole to the outside and note how much straight metal duct you will need.

Determine how many turns you need to make with the rigid metal duct structure to decide how many elbow joints to buy; the most direct route is always best.

However, you must use a curved elbow joint where the duct connects to the drain pipe and another where it connects to the outside vent.

If the washing machine drain pipe isn’t sitting in front of the outside vent, you may also need an elbow vent to turn the duct to the side.

Once you’re done with the preparations, move on to the next step.

Step 2 of 7: Use the Elbow Joint

Slide one elbow joint on the washing machine drain pipe output and one on the outside vent. Use the joint’s solid end instead of the crimped end.

Measure the distance between them. Deduct the size of an elbow joint if you need to add another corner in your duct design to reach the outside vent.

The elbow joint reinforces the whole structure and acts as a frame. So be careful when you install it.

Now, if you’re done working with the elbow joint, move on to the next step.

Step 3 of 7: Cut the Metal

Put on your heavy gloves. It’s time to cut some metal ducts to make the whole structure from scratch.

Start by cutting the straight metal duct to the sizes necessary to fit between the elbow joints. Use tin snips for this task.

Ideally, there would only be one section of the duct leading from the washing machine drain pipe to the outside vent.

Once you’re done with this step, jump right onto the next step.

Step 4 of 7: Align and Connect the Seams

It’s time to get some alignment done. So, let’s start with the seams.

Pull the long ends of the duct together, aligning the seam. Push down on the seam to connect the seam and form a circle with the metal.

Start at the other end of the duct for this. Be ready to put some focus on this job because the alignment is important.

If you’re done with this step, move on to the next step.

Step 5 of 7: Connect Duct to Elbow Joint

Now, you’ll have to start connecting the duct to the elbow joints. This can take some time to complete.

Push one end of the duct over the crimped end of the first elbow joint. Cover the area where the two pieces connect with metal foil tape.

Avoid duct tape, which doesn’t seal gaps well and loses adhesion faster than the foil tape. So, it’s better to use some metal foil tape here.

Also, avoid screws to connect the pieces. They create an obstacle that attracts lint buildup.

Now, move on to the next step once you’re done with this one.

Step 6 of 7: Connect the Other Elbow Joints

Continue connecting the other elbow joints to the duct. Follow whatever you did in the previous step.

Insert the crimped end of the second joint into the duct. Repeat with additional joints if necessary, taping the pieces together.

Once you’re done with this step, move on to the final one.

Step 7 of 7: Apply Finishing Touches

It’s time to add the final touches to the whole process. Let’s put an end to it then, shall we?

Lay a U-shaped pipe strap around the duct and screw it in place without compressing the duct.

Drill a pilot hole for each screw into the drywall and push in drywall anchors if you’re screwing it into the drywall.

Drive screws into the anchors for a secure hold. Each straight length of the duct should have one pipe strap every 8 feet to reduce the strain on the taped joints.

Once you have completed this step, your washing machine drain pipe has been vented. Those were all 7 steps that you needed to go through.

Frequently Asked Questions

Why is a washing machine drain vent necessary?
If the drain of your washing machine fits tightly into the drain, you definitely need a washing machine drain vent. It allows air in which prevents the possibility of a vacuum forming that could affect the water draining from your washing machine. You should also install a vent if your washing machine is more than 4 feet from the vent stack, as this will make sure there’s ample room for the washing machine to drain properly.
Why do we need a P-trap?
If you create a waste pipe for any fixture that needs draining, including a washing machine, and the drain doesn’t have a P-trap, you’re creating a dangerous situation. The pool of water in the bottom of the trap effectively seals sewer gases inside the pipes, and if you omit the trap, the gases have a direct route into your house. Besides being laden with harmful organisms that you can inhale, some sewer gases, such as methane, are flammable. If the washer is in an enclosed area, you could actually create a fire hazard by omitting the trap.
What are cheater valves?
The washing machine is usually on a lower floor, and running the vent upstairs to tie into the main vent can involve a certain amount of wall repair. To avoid this, some plumbers install an air admittance valve — sometimes called a cheater vent. It has a spring-loaded mechanism that opens the valve to admit air whenever water is flowing and creating negative pressure. These valves aren’t legal everywhere, so check with your local building department before installing one. If its use is permitted, you must install it in an accessible location with plenty of air.
Why do we need a standpipe?
The correct way to drain a washing machine is to install a standpipe. That is a vertical length of pipe that connects to a P-trap that, in turn, connects to the drain. The top of the standpipe must extend above the overflow level of the washing machine, and it must be properly vented. Installing a standpipe isn’t a difficult plumbing maneuver when the laundry area has unfinished walls. You simply run a horizontal pipe from the drain to the washer, keeping a slope of 1/4 inch per foot toward the drain. You then glue on a P-trap and a standpipe and affix the standpipe to stud with strapping.

Wrapping Up

We hope our guide on how to vent a washing machine drain pipe helped you out. We laid out these 7 steps to make things easier for you.

Try following the steps with a proper focus to get the best results out of your work. We hope you get the job done well.

If you want us to cover something else or if we missed something, let us know by giving some feedback. You can use the comment section below.

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