Yes, every drain needs a separate vent to ensure the plumbing works properly and waste is removed. What happens if a drain isn't vented? Without drain vents, gases build up in plumbing pipes and drains and keep water from flowing freely.
Before anything else, you should keep in mind that every drain needs to have a trap installed and every trap will need a vent associated with it. So now you see how these plumbing elements are interrelated.
Without these vents, wastewater will empty into drain traps, making it easier for gases to escape from the drains. A bit of water should always remain inside the traps behind or under each drain to ensure the pipelines eliminate waste without risking gas seepage and odors.
Sewer Gases
In addition to these issues, improper venting of a sink drain can also lead to more serious problems, such as sewer gas leaks. Sewer gas is a mixture of toxic and non-toxic gases that are produced by the breakdown of waste materials.
Some types of broken ventilation can even actively suck up sewer gas and release it through your sink drain or toilet bowl. When this happens, stinky sewer gas will enter your home.
Every plumbing fixture needs to have a vent to work properly. Bath tubs, toilets, washing machines and kitchen sinks need the biggest plumbing vents.
Having a properly vented kitchen sink not only improves drainage and reduces pipe damage, but it also helps keep your home safe from sewer backups and the associated health risks.
Your drains are connected – One of the main reasons your toilet gurgles when your washer machine drains is because your washer machine is connected to the toilet drain. This isn't uncommon. Your washing machine might have been placed in between your toilet and sewer stack.
The Importance of Toilet Ventilation
The pipes connected to your toilet transport waste and water from the system. The vents deliver fresh air into the system while removing gas and odors that are byproducts of the waste disposal process.
Venting is necessary for bathroom plumbing systems to prevent blockage. All pipes in your home, particularly for toilets, sinks, and showers, require proper venting. It protects the trap on the drain pipe. In addition, it helps you secure your wallet, fittings, time, and even the pipe itself.
A vent is a necessary part of the drain system for any plumbing fixture. Its purpose is to equalize pressure in the pipes and prevent a vacuum from forming as the fixture drains.
In general, the vent should be as close as possible to the fixtures it serves. This proximity helps ensure the vent can effectively equalize air pressure and prevent sewer gas entry. However, there are some common guidelines to consider: The vent should be within 5 to 6 feet of the fixture drain it serves.
This concept, known as vacuum pressure, is in effect in your bathtub's drain. Without venting, the water has difficulty moving, and the gurgling sounds you hear are from your drain gasping for air. But do you need to vent a bathtub? Absolutely!
Drain-waste-vent (DWV) pipes carry waste and water smoothly out of the house without gurgles or fumes. This requires an air passageway behind the water. Vent pipes extend from the drainpipes up through the roof to provide that passage while also carrying odors out of the house.
Yes, the toilet and sink can share the same vent, as can the shower. It's common to have one main vent pipe for multiple fixtures, although you might need a larger pipe. You should check with local building and plumbing codes to confirm you'll have adequate piping for your home.
If your sink is backing up only when the washing machine is draining, for example, the likelihood is that the blockage is in the washing machine pipe. A clogged plumbing vent pipe may also be the culprit. Without proper air pressure, your sinks, shower and tub water might drain slowly.
Shared drains are a common occurrence in apartments, but it is unlikely to be the case for most homes. Certainly, if you choose to install a downstairs bathroom that connects to the kitchen then it makes sense for them to share a drain.
When drain lines aren't properly vented, low pressure inside the pipe can suck water out of the traps, letting sewer gas in. Air pressure imbalances inside the drain pipe can restrict water flow and cause sluggish draining, often mimicking a partial clog inside the pipe.
Yes, every drain needs a separate vent to ensure the plumbing works properly and waste is removed. What happens if a drain isn't vented? Without drain vents, gases build up in plumbing pipes and drains and keep water from flowing freely.
Signs of a clogged or blocked vent include gurgling sounds from drains and toilets, slow-draining fixtures, foul sewer odours around sinks and drains, decreased water pressure, and bubbles coming up through the toilet bowl. A clogged vent pipe prevents proper airflow and allows sewer gas to back into the home.
Yes, every fixture needs it's own vent. No, each vent does not need to go independently through the roof. They can be combined so you only have one or two vent stacks through the roof.
If you decide to hire a licensed plumber near you to handle the fix, you can expect to pay between $150 and $200 for this service, although it could be more depending on the severity of the problem.
Average Flat Rate
Some plumbing jobs are billed at a flat rate. As of 2025, the average plumber rates for larger repairs are typically between $500 to $800, while smaller jobs like repairing toilets, sinks, faucets, or bathtubs typically range from $125 to $350.