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What Is a Plumbing Vent and Why Do I Need It 2023

Plumbing Vent

What Is a Plumbing Vent and Why Do I Need It 2023

Also referred as ‘the venting system’, plumbing vents are special types of pipes or a network of pipes that lead from one home appliance to the outside environment.

They usually lead to the roof of your house but you can also place them somewhere else if you want to. They are usually composed of several pipes that serve their purpose well, all the time.

Importance of Plumbing Vents

Plumbing vents may be new to your ears but they are not new in the plumbing industry. They have always been part of plumbing and play a very important role that you’ll later appreciate. They are so important in plumbing because they carry sewer gases from appliances to the outside world.

Instead of carrying water inside your house, as normal pipes do, these special pipes help prevent sewer gases to get into your home that could potentially make you sick. They provide a safe and effective gas passage so you and your family can sit in your couch comfortably without the nasty smell of sewer gases.

What Is a Plumbing Vent and Why Do I Need It 2023

Aside from allowing oxygen to enter your piping and making sure that both water and waste move properly through the pipes, vents are also responsible for maintaining neutral air pressure in your piping system.

Neutral air pressure must be well maintained to avoid either positive air pressure or negative air pressure to overwhelm your plumbing system. Too much positive or negative air pressure cause sewer gases to enter your home and you won’t like the smell of those gases.

With all these information, it’s safe to say that these vents are indeed significant in a plumbing system. However, you must know that vents are not necessary to be installed. Yes, they are important but they are not mandatory to every household.

What the Heck is a Plumbing Vent and What Does it Do?

While plumbing vents are important, there are unique cases that a plumbing system may not be in need of vents. If you’re not using modern, not to mention expensive, piping then that’s the time that vents are a must in your house.

According to building codes, a home with appliances must have traps in them to prevent gases from entering into the home. Plumbing vents are the traps that can play the role. So, it’s up to you if you want them installed or not.

How to clear the blocked sewer line

Can clogs get into vents?

Yes. Even though these pipes are considered special, they are still pipes and they are not invincible to clogs. When winter comes, ice can just build and cause clogs to build up on vents which can affect their performance.

Small debris and even small animal’s dead body can clog the vents which is why it’s necessary that you check them often.

If you won’t do something about the clogs on your plumbing vents, you’ll most likely experience one or all of these: slow drainage, strong glugging sounds might be heard while a fixture drains, or worst comes to worst, gas may escape and plagues your home.

When all these things happen, you may call for a professional plumber to fix the issue and get your plumbing vents back working again.

About Plumbing Vents and Their Purpose in Your Plumbing System

The plumbing vent, also known as a vent stack, helps regulate the air pressure in your plumbing system. Just as drain pipes remove water and waste from your home, the plumbing vent pipe – also known as a plumbing air vent – removes gas and odors. … The vent stack is the pipe leading to the main roof vent.

What Are Plumbing Vents?

We depend on indoor plumbing, so plumbing problems can disrupt our households. Learn what issues can cause your vent pipes not to work properly and what to do.

Why Your Home Needs Plumbing Vents

Most homeowners will encounter a plumbing issue now and then, but diagnosing the problem involves more than just checking the water pipes. Plumbing vents can also become clogged or damaged, causing stoppages and a host of other issues.

Understanding this sensitive part of your plumbing system is important in order to keep drains flowing smoothly in your home.

What is a Plumbing Vent?

The plumbing vent, also known as a vent stack, helps regulate the air pressure in your plumbing system. Just as drain pipes remove water and waste from your home, the plumbing vent pipe – also known as a plumbing air vent– removes gas and odors.

It also allows fresh air into the plumbing system to help water flow smoothly through the drain pipes. However, no water runs through the plumbing vent pipe.

It is a vertical pipe attached to a drain line and runs through the roof of your home. The vent stack is the pipe leading to the main roof vent. It channels the exhaust gases to the vent and helps maintain proper atmospheric pressure in the waste system.

Why Plumbing Air Vents Are Important

Your home’s plumbing system is designed to efficiently remove water and waste. Its drainage and vent functions are actually two systems that work together.

Drainage pipes carry waste out of your home to either the city sewer or a septic tank. Vent pipes supply fresh air to each plumbing fixture in the house, which helps the system move water through the drainage pipes each time a toilet is flushed or a sink is drained.

Plumbing air vents also prevent sewer gases from entering the home and allow wastewater gas and odor to escape. Plumbing vent pipes are located on roofs, away from windows or air conditioning units, so that the fumes can easily dissipate.

Problems With Plumbing Vent Pipes

When plumbing air vents or vent stacks do not work properly, neither will your home’s plumbing drainage system. If you hear gurgling sounds coming from your drains, see standing water in your sink or bathtub, or notice a slow drain in the bathroom or kitchen, a blocked vent may be the issue.

When a plumbing vent pipe or vent stack is blocked, negative pressure builds up in drainage pipes and water flow is interrupted. Though you may have success clearing a clogged drain yourself, stoppages will continue to occur if a blocked vent is the culprit.

What Is a Plumbing Vent and Why Do I Need It 2021

Ongoing stoppages and slow-flowing drains can lead to sediment forming inside the drain pipes. This can further damage your plumbing system and may result in hefty pipe repair or replacement costs down the road.

If you can’t clear a slow-flowing drain with a plunger, auger or drain cleaner the vent blockage may be severe. If the plumbing air vent or vent stack becomes completely blocked, a vacuum will form and you will no longer hear gurgling.

You will also be able to smell sewer gases in the rooms where the affected fixtures are located. This is a problem that requires immediate attention from a plumbing professional.

Plumbing Vent
Plumbing Vent

American Home Shield warranties cover a variety of plumbing issues, offering peace of mind when it comes to one of your most important investments – your home.

Does every plumbing fixture need a vent?

Every plumbing fixture must also have an attached vent. The top of stacks must be vented too, via a stack vent, which is sometimes called a stink pipe. All plumbing waste fixtures use traps to prevent sewer gases from leaking into the house.

How do I know if my plumbing vent is clogged?

The top three signs your plumbing vent is clogged include:

  1. Sputtering, gurgling toilets. When airflow is inadequate in a vent because of size or blockage, the plumbing pressure will be greater than the air in the bathroom. …
  2. Slow drain. …
  3. Strong sewer gas odor.

How do you unclog a plumbing vent?

If you can see but can’t reach, run a plumber’s snake down the vent pipe. To continue, feed the end of a garden hose down the vent and have someone on the ground turn on the water. Listen carefully for water backing up and a sudden whoosh as the weight of the water pushes the clog back down the drain.

What happens if plumbing is not vented?

Poorly-vented drain lines will not be able to effectively move wastewater and solid waste out of your building. This could lead to problems such as overflowing drains, backed-up toilets, and similar plumbing issues.

Plumbing vent pipe

Plumbing vents are pipes that extend from the waste pipes to the outside of the building, often going through the roof. The vent pipes allow the sewer gases to escape to the outside, rather than being released inside the house. The vent pipes also allow oxygen into the waste pipes

Plumbing vent roof

It is a vertical pipe attached to a drain line and runs through the roof of your home. The vent stack is the pipe leading to the main roof vent. It channels the exhaust gases to the vent and helps maintain proper atmospheric pressure in the waste system.

plumbing vent pipe installation

vent stack

It’s a vertical pipe that doesn’t carry any waste and its main purpose is to regulate air pressure throughout the areas of your home’s plumbing system. It is also called a plumbing vent, and it keeps gases and smells from remaining inside the septic system.

plumbing vent pipe code

Vent pipes shall not be less than 11/4 inches (32 mm) in diameter. Vents exceeding 40 feet (12 192 mm) in developed length shall be increased by one nominal pipe size for the entire developed length of the vent pipe.

plumbing vent pipe clogged

If you can see but can’t reach, run a plumber’s snake down the vent pipe. To continue, feed the end of a garden hose down the vent and have someone on the ground turn on the water. Listen carefully for water backing up and a sudden whoosh as the weight of the water pushes the clog back down the drain.

Vent Pipe’s First Benefit

When it comes to household plumbing systems, most people know drain pipes and supply lines. Drain pipes allow water and waste to flow out of your home and into the sewer system. A water or supply line brings the water in and lets you fill your sinks, bathtubs and washing machine.

A plumbing vent pipe works alongside your drain pipes, except it doesn’t carry water. Instead, it regulates the air in your plumbing system.

Also called a vent stack or plumbing air vent, the vent pipe regulates airflow to assure waste and water flows through pipes that drain out of your house. It prevents a vacuum that causes slow or no drainage.

Clean drain pipes can only do their job when the vent pipe works. Each plumbing fixture in your home requires air to move the water through the drainage pipes.

Vent Pipe’s Second Benefit

Your plumbing vent’s second purpose is to remove sewer gases. It’s common for such gases to flow from the sewer system into your home. This build-up of gases not only causes a foul odor, but it can also be dangerous.

That’s why your plumbing vent pipe on your roof. It’s installed away from air conditioning systems and windows so those gases and odors don’t get back into your home.

Common Types of Plumbing Vents Pipes

When you install a new plumbing fixture like a sink, you need to make sure it’s properly vented. Here are the different types of vent pipes and where they’re usually located.

  • True vent: This is the most common type. It’s a vertical pipe attached to your drain line. Because no water runs through it, it vents from the roof.
  • Common vent: Use a common vent between two fixtures installed on opposite sides of a wall, like back-to-back sinks. They’re connected to the stack with a sanitary cross.
  • Re-vent pipe or auxiliary vent: This type attaches to the drain line or behind the plumbing fixture. It runs up and over to the main vent that goes to the roof.
  • Air admittance valve (AAV): This is actually a valve that opens when wastewater drains. It lets air in and uses gravity to stop any gases from getting into the room. Usually, these vent for more than one fixture.

Make sure to check building codes and to consult with a professional before you install a venting system.

Potential Vent Pipe Problems

Blockages in your vent pipe or stack cause a buildup of negative pressure in your drainage system. That means water can’t flow out of your home efficiently, if at all.

While many types of drainage issues you can fix yourself, a blocked vent is more difficult. If you often have drainage problems, a blocked vent might be the cause.

More often than not, you should seek professional help immediately. The more your pipes back up with wastewater, the more likely sediment will form in them. That sediment can lead to costly repairs if unchecked.

A blocked vent can also cause gurgling sounds in your drains, standing water in sinks and tubs, and much slower drainage. More dangerous is the buildup of sewer gases. That’s recognizable by its odor.

When you can’t fix these issues with a plunger, drain cleaner, or even an auger, a professional plumber will inspect your pipes, diagnose the issue and fix it.


Everyone is familiar with the fact that pipes are a major part of the plumbing. Folsom certainly has its fair share of these well-known plumbing pipes. What isn’t so well-known, yet are still a major component to any plumbing system, are plumbing vents.

Never heard of these? No worries. Many people haven’t. Here is a brief overview of what a plumbing vent is and how it works.

Plumbing Vents in Folsom

A plumbing vent is basically a special pipe (or network of pipes) that leads from an appliance located inside your home to the outside of your home. Although not always, many of these will lead to the roof of your home.

Also, many vent pipes are comprised of more than one pipe. So what purpose does a vent serve with regard to your plumbing? Folsom residents are about to find out.

What Do They Do

Unlike the other pipes in your system, vent pipes do not carry water. Instead they carry sewer gases safely from the inside of your home to the outside environment. This is an extremely important part of your home plumbing. Residents should always ensure these vents are in good working order.

Sewer Gases

Sewer gas can make you very sick. Without these vent pipes, these gases would build up in the system and eventually emanate out of your drains and taps and into your home. The vents allow the gases to escape so they won’t build up.