Stop The Sewer Vent Pipe On The Roof From Smelling Up

No homeowner wants to step outside to smell sewage in their yard. That awful smell is most likely coming from the sewer vent pipe. Even though it’s all the way up on your roof, you will still be able to smell the stench down in your yard. So, why is this happening and what can you do to get rid of it?

Bad smells coming from a sewer vent pipe are caused by a clog. The clog prevents air from passing through and collects bacteria and sludge. This results in a foul plumbing odor on your property. The only way to fix this problem is by unclogging the sewer vent pipe with an auger.

Can you smell the plumbing when you’re outdoors? This is a problem you’ll want to address before your neighbors start to complain. Today, we’re going to discuss how this odor is caused and the most effective way to get rid of it. Read on to learn more.

What is a Sewer Vent on the Roof?

The sewer vent on the roof is responsible for removing sewage and regulating the air pressure in the plumbing system. These vents are the reason why you never smell the gases and odors that are in the plumbing.

Every residential property will have a sewer vent on the roof. This is because building codes do require every plumbing fixture to have a vent. Plumbing gases would leak into your house if these vents weren’t installed. That would put everyone in your household at risk of getting sick.

The sewer vent is always installed on the roof because it’s the easiest location to allow the gasses to escape and travel away from the house. When you start to smell the sewer smells in your yard, it’s a sign that there’s a problem in the pipes.

Why Does Your Sewer Vent Pipe Stink? 

That awful smell is due to a clog which is preventing the air from moving in the pipes. This is a very common problem that happens in most households. Luckily, it’s also easy to fix without having to call in a professional. Let’s take a look at what you need to know.

Your Sewer Vent Is Clogged

A clogged pipe can cause this smell in your yard because the gases and air can’t escape. It doesn’t matter what the source of the clog is, there will be a bad smell. Things like soap suds and hair can smell just as foul as human waste.

Of course, there are many funky smells that are related to plumbing. If a homeowner smells something bad in their yard, how do they know for certain that it’s the sewer vent pipe? There are a few other signs of a clog other than a foul odor.

Sewer Vent Diagram
  • Gurgling noise in the drains and toilet
  • Water drains slowly in sinks or the tub
  • Weak flushes in the toilet

It’s important to address clogged sewer vents right away. That smell in your yard could make it into your house if you set the problem sit. It could also lead to damage to your plumbing system because water won’t be able to flow properly.

How to Unclog Your Sewer Vent Pipe 

You can unclog your sewer vent pipe DIY. Before you start, you will need to access the pipe from the roof.

On the roof, you’ll notice multiple vents. The sewer vent pipe is the one that looks similar to a toilet pipe. It usually has a 3-inch diameter and is made from PVC or cast iron. Let’s take a look at what you need to do to unclog this pipe.

Step 1: Prepare To Work On The Roof

Safety should be your #1 priority before attempting any repair job around your home. Extra caution should be taken when you’re working on top of a roof. You will want to ensure you have a safe area to work on and the right gear while you’re up there.

Before you make any plans to unclog the sewer vent pipe, you should check the weather forecast. It’s safest to work on your roof during a dry day (unless you have wet-weather safety gear). You should avoid rooftop work in extreme heat and cold as well.

So, what items should you have ready to work on top of your roof?

  • Ladder
  • Safety gloves
  • Non-slip footwear
  • Fall protection (safety harness & lanyards)
  • Safety glasses
  • Face mask/respiratory protection

There are a few things that experts want you to know before working on the roof as well.

  • Always make sure ladders are safely secured.
  • Become familiar with the roof material you’re going to be stepping on. Roofs made from slate or tile put you at a higher risk of slipping.
  • Keep the work area clear. It’s a good idea to sweep the roof before working on it. If you are using any ropes or cables, make sure they’re secured underfoot so they don’t cause you to trip.

Step 2: Use An Auger To Flush The Vent

You can tell if the vent pipe is clogged because when you look down it, you won’t be able to see anything. When the pipe is clear, you should be able to see all the way down your plumbing pipes (with the help of a high-power flashlight).

Once you determine you have a clog, you can clear it with an auger and a hose. Let’s take a look at what you need to do.

  1. Unlatch the clasp that secures the auger/plumbing snake in place. Slowly release the auger into the vent pipe. Continue directing the auger down the pipe until you meet the clog.
  2. Move the auger around to push the clog. This could push the clog out if it isn’t severe.
  3. Make sure you’re using a hose that’s connected to a water supply. Place the hose into the vent and travel it down to where the clog is.
  4. Turn the water on. Move the hose up and down, similar to how you would with an auger. Do this until you feel the clog move.

Step 3: Add A Vent Cover Or Protection

After you have removed the clog, you should protect the vent pipe. Clogs can occur from outdoor forces as well. An open sewer vent pipe can catch leaves, dirt, and debris during storms. It’s also an open invitation for rodents to crawl inside.

That is why you should add a cover to the pipe. This is something you can make DIY using steel mesh.

What you need: steel mesh, tin snips, hammer, wire rope

  1. Take the roll of steel mesh and place it over the opening of the sewer vent pipe. This is how you will figure out how much mesh you need to make a cover.
  2. Make sure there are a few extra inches of mesh on each side of the pipe before using the tin snips to cut it.
  3. Place the piece of steel mesh that you cut over the top of the pipe’s opening. Bend the mesh to fit it against the pipe. Fold over the excess pieces of steel mesh to keep everything in place.
  4. Gently tap the wire with a hammer to secure it to the pipe. Go all the way around the pipe with the hammer.
  5. Take a long piece of wire rope and wrap it around the steel mesh cap. Once both ends of the wire meet, begin twisting them around each other. Gently tug the wire to ensure it is tight against the pipe. Make sure it’s not loose because it will fall.
  6. Pull both ends of the rope to make sure it’s tight enough. Use the tin snips to clip off any extra wire.

Step 4: Expand The Vent Stack

Is your vent continuously getting clogged due to outdoor factors? You never know what the wind will bring your way. For this reason, you could benefit from expanding the vent stack.

Expanding the vent stack is easy and affordable. You can purchase PVC couplers from a local hardware store to extend the vent stack.

What you need: sealant, PVC couplers (2-inch and 2-foot)

  1. Place the sealant in a caulking gun to make it easier to use. Determine how tall you want the pipe to be. If you want to shorten the 2-foot coupler, you can use a hacksaw to get the preferred length.
  2. Start with the 2-inch coupler. Put a generous amount of sealant around the inner ring of the coupler.
  3. Place this coupler on top of the sewer vent pipe. You will need to twist it around to secure it in place.
  4. Set the 2-foot PVC coupler into the 2-inch couple before the sealant dries. Make sure it’s in a secure position before you let go.

How Much Will it Cost To Fix Your Sewer Pipe?

Now that you have a better understanding of how to fix the sewer pipe, you might be wondering how much it will cost you. You will only need to cover the cost of materials if you’re unclogging the pipe yourself. Let’s take a look at some of the average costs.

PartAverage Cost
Auger$25 to $100 (small, no-power) or $250 to $1,000 (machine)
Steel mesh$20 to $25
Wire rope$30 to $35
PVC Sealant$15 to $35
Couplersstarts at $1

Most clogged sewer vent pipes don’t require you to hire a professional. However, there is a possibility that you could come across a clog that is too complicated or a damaged pipe. In this situation, you’ll need to factor in the cost of a plumber.

Plumber rates do vary between the area you’re in and how extensive the work is. It’s common for plumbers to charge around $100. However, the rates could be anywhere from $25 to $200 per hour.

When Should You Hire A Professional?

Unfortunately, not every plumbing problem can be fixed DIY. It’s best to contact a professional if you notice that the clog continues to come back. This is caused by a deeper problem that will require a professional inspection and drain cleaning service.

You should also consider hiring a professional if you’re not comfortable working with heights or familiar with the tools needed for the job. Unclogging a vent pipe does put you at risk of coming in contact with sewer gases. This is why you may feel more comfortable contacting a professional.

There are benefits to hiring a professional. They know how to detect the problem correctly without any second guessing. Professionals will also have the right tools and equipment for the job. This saves you from having to buy them yourself. Many plumbers also provide a warranty on their work, just in case the clog comes back.

How To Prevent Future Clogs? 

Now that you know how to get rid of that odor, you’ll want to prevent it from coming back. One of the best courses of action to take is making a steel mesh cover, as discussed in step 3. This will prevent factors out of your control from clogging the pipe.

You should also consider regularly flushing the sewer vent. Doing this at least once a year can help you prevent these unwanted clogs.

Regularly Flush The Sewer Vent Pipe

You can use a garden hose to manually flush the sewer vent pipe. In fact, you don’t have to wait for a clog to happen to do this. Flushing the sewer vent pipe with water will help clear debris, dirt, and other things that make their way into the pipe.

Flushing the sewer vent isn’t complicated. You just need to run water from the hose into the vent pipe. It’s recommended to use hot water if there is a lot of debris build-up or you haven’t flushed the sewer pipes in a long time.

This is important because the debris and dirt that gets into the pipe sticks to it. As more soap suds, hair, and other particles go down the drain, they stick to the buildup. This is what causes a clog. By flushing the sewer vent, you will be breaking away any buildup that has occurred.


Is there a foul sewage smell in your yard? This happens because there is a clog in the sewer vent pipe. We talked about some of the ways to prevent clogs from the outside today. However, you can also benefit from inspecting your indoor drains as well.

Drain catchers and tub shrooms are excellent ways to catch hair and prevent clogs from occurring. It’s also important to make sure you aren’t flushing items down your toilet other than human waste and toilet paper.