Everything You Need to Know About Plumbing Vents

Everything You Need to Know About Plumbing Vents

Home plumbing venting systems are often an overlooked part of your plumbing system. But plumbing vents are vital because they help remove sewer gases from the home, which is a major cause of home plumbing odours.

Sewer gas is created by decomposing organic matter such as food scraps and paper products entering the plumbing lines when people don’t clean their sinks or garbage disposals. The result can be unpleasant smells, bad tastes in tap water, corrosion in pipes and fixtures, and an increased risk for mould growth on all surfaces inside the house with poor ventilation.

It’s important to know about how plumbing vents work so you can recognise when there may be a problem with your plumbing vent system!

Today, we explore plumbing vents, looking at what they are, how they work, and common problems. We’ll also explain what to look for to know if your home has a venting problem.

Table of Contents

What Is a Plumbing Vent Pipe?

If you’ve been living in your home for a while and have never looked at the plumbing venting system, you might wonder what a plumbing vent pipe is.

Plumbing vent pipes are also known as plumbing vents. They are pipes that serve the purpose of releasing sewer gases from plumbing fixtures in your home’s plumbing system to help prevent odours and musty smells, plus they reduce damage to plumbing components caused by corrosion.

Where can you put plumbing Vents?

The plumbing vent is typically installed near the highest point of the plumbing drainage system. While they are most commonly positioned vertically on a roof, they can also be positioned horizontally, coming out of an external wall.

Should Plumbing Vents Be Capped?

A common question asked about plumbing vents is whether they should be capped or not. While plumbing vents can be capped, it is not advisable to do so because if the plumbing vent becomes blocked for any reason, sewer gases may accumulate in your plumbing system and cause damage to plumbing fixtures and components such as faucets.

Why Do Homes Need Plumbing Vents?

Your plumbing vent has a very important task. It needs to remove sewer gases from your plumbing before they can accumulate inside of your plumbing system and cause problems with odours, harmful toxins and health risks.

These gases may include hydrogen sulphide gas, ammonia, methane, and other toxic gases that can pose health risks if they accumulate inside of your plumbing pipes.

There are a few reasons why you need plumbing vents:

  • if there is a natural build-up of gases from plumbing activities such as flushing the toilet, showering and using plumbing fixtures such as sinks or dishwashers;
  • if there are plumbing vent restrictions such as plumbing vents that are blocked by dirt, debris or fallen leaves
  • if your plumbing venting system is poorly sized; and
  • if plumbing vents become disconnected.

If you don’t have plumbing vents then sewer gases will accumulate inside of your plumbing pipes. This can lead to plumbing odour problems, corrosion damage and health risks.

How Does a Plumbing Vent Work?

The main function of a plumbing vent is to prevent back-flow from entering into homes through their plumbing systems by releasing any accumulated pressure. Along with preventing back-flow, it also prevents water hammers and provides ventilation for combustion appliances such as furnaces and water heaters.

Plumbing vents work by releasing the plumbing drainage system pressure to the outdoors. This helps prevent plumbing odours, sewer gas problems, and pipe corrosion when plumbing back-pressure build-up won’t be released.

The plumbing venting system is designed with one or more plumbing vents to allow for a natural flow of air through your plumbing system. The plumbing vent should have a certain slope determined by plumbing codes to allow for air to be drawn through the plumbing vents.

The plumbing venting system also includes anti-syphon breaks as part of the plumbing vent pipes. These prevent back-flow from entering into your plumbing system from your plumbing fixtures and appliances by detecting when they don’t have water and releasing plumbing drainage system pressure to prevent plumbing odours.

What Are the Types of Plumbing Vents?

There are various types of plumbing vents, including individual plumbing vents, continuous plumbing venting and two-pipe plumbing venting.

Individual plumbing vent

Individual plumbing vents are plumbing fixtures with their own plumbing vents to release sewer gas pressure. These include toilets, sinks, tubs and showers. Individual vents are typically used to vent fixtures too far away from a branch or stack to be wet vented, or fixtures connected to a soil or waste pipe downstream of a toilet.

Continuous plumbing venting

A continuous vent extends from a vertical soil or waste pipe to one or more fixtures on the same story. Continuous vents, like all plumbing vents, protect the fixture’s trap seal(s). Continuous vents are most commonly used to serve wet vented branches.

Continuous vents are named similarly to individual vents when connected to a vertical soil or waste pipe, but the sizing requirements differ. It is a Soil or Waste Stack if the soil or waste pipe passes through multiple storeys.

Two-pipe plumbing venting

Two plumbing pipes that release plumbing system pressure to the outdoors.

This plumbing system consists of a trap with a “T” pipe on it which releases plumbing system pressure by going out through plumbing vents. The T-pipe has a cleanout feature so the homeowner can access the plumbing vents for routine maintenance and cleaning purposes.

What are the Rules & Requirements for Venting?

You need to follow plumbing venting rules and requirements when venting your plumbing fixtures.

Each country and state may also have different rules to follow. For example, in New Zealand, plumbing venting must comply with the specifications outlined in the Compliance Document for New Zealand Building Code.

This document outlines all building requirements for residential plumbing vents, including the material, diameter, termination, height and water level for installation.

You should also check with your local authority having jurisdiction (AHJ) to find out what plumbing venting rules and requirements you need to follow. They will be able to provide plumbing venting information for your location regarding plumbing vents and plumbing vent plumbing systems.

What Are Common Vent Pipe Problems?

A plumbing vent is an important part of your plumbing system, so it’s very important that you look after yours. If it isn’t working properly, the problems can become expensive and more difficult as time goes on, as corrosion starts to set in and plumbing problems arise.

The most common plumbing venting problem is a plumbing vent that has been blocked, which traps plumbing system pressure and causes plumbing odours as well as associated health hazards. Other plumbing venting problems include

  • dirty or clogged plumbing vents
  • plumbing vents sticking out of the roof such as those on flat roofs
  • plumbing vents that are too short or plumbing vent plumbing system in which the plumbing vent makes a 90-degree turn in a straight line.

What Are Common Signs of Poorly Vented Plumbing?

There are plumbing vents in the plumbing system, and you should keep an eye on what happens to them or when they become blocked.

The most common signs of poorly vented plumbing include:

  • sewer smells around your plumbing fixtures and drains
  • discolouring of sinks and tubs with age
  • damp, musty feeling near plumbing fixtures and drains
  • water leaks
  • dry and empty toilet cisterns
  • water takes a long time to drain
  • gurgling sounds as water goes down the drain

How to Clean Your Plumbing Vents

To keep your plumbing vents working for many years, it’s essential to clean them regularly.

Some plumbers recommend having your plumbing vents cleaned every three months, but we think it’s perfectly ok to go as far as six months without cleaning plumbing vents.

Flexible plumbing vents are usually easily accessible and can be cleaned with an ordinary plumbing snake. However, for plumbing vents that are located in difficult to reach plumbing areas, you should call professional Auckland plumbers such as iSpecialise. We have all the tools and equipment needed to get to the hardest-to-reach locations, leaving your vents clean and clear and working well for years to come.

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How Can I Fix Problems With Plumbing Vent Pipes?

The first thing to do if your plumbing vent system is blocked is to clean them. This may take time because you will need to use an ordinary plumbing snake, but it will usually loosen any debris stuck on them, which can then be removed with a plunger or by flushing water through the plumbing section.

A plumbing snake won’t work with severe clogs because you’ll need a plumbing auger to break up the blockage which is usually caused by tree roots. However, if you have a plumbing clog or your plumbing vent has been blocked, it’s important that you don’t try and fix this yourself – call an Auckland plumber who has the right tools and experience in this area, such as iSpecialise. We will ensure that your plumbing vent plumbing system is fixed correctly and safely.

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Your plumbing vent system is an important part of your plumbing, and it’s very important that you look after plumbing vents to ensure they work for many years. Even a clogged plumbing vent can cause plumbing problems, so it’s best to have them inspected by a plumbing professional – such as iSpecialise.

We will check your plumbing vent plumbing system, and if they are blocked, we’ll clean them. If they’re beyond cleaning, we’ll use plumbing augers to remove any blockages caused by tree roots or other debris, leading to plumbing problems.

We provide plumbing services in Auckland, including plumbing vent systems. We provide free quotes with no obligation, so contact us today for an Auckland plumbing company you can trust.

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