How to Vent a Toilet

How to Vent a Toilet

Are you adding a new drain or toilet to your home? If this is going to be your next DIY project, then you must realize that the most important consideration here is the toilet vent. All toilets need a plumbing vent, and this is also true for sinks and showers. The plumbing vent pipe system makes sure that your new toilet flushes correctly. It is also put there in place to ensure that there is no sewer gas getting out of the drain pipe and into your home.


Importance of a Toilet Vent

Importance of a Toilet Vent

If you know a little bit about plumbing and installing a drain, then you will have a good idea of why plumbing vents are necessary. Else, here is a list of the functions of a toilet vent for you to read through. After reading the list, you will realize that your toilet can’t go without a drain pipe or a vent, even if it is going to be an outdoor bathroom. Here are the reasons why you need a toilet vent:

1.  To prevent bubbling

Water runs through the toilet even if it isn’t used. Without proper toilet venting, you will see air bubbles coming up the surface originating from the waste pipe. It is because the trapped air inside the pipes will have to find a way out. If there is no vent, then it will go up the toilet bowl surface. You can practically see the bubbles before you get into the toilet seat. If you’re finicky type of a person, you surely don’t want that.

2. To ensure seamless flushing

The right type of vent allows toilet water to get pushed down at the desired pressure. Any blockage on the toilet drain, including air that could be taking up space, will prevent your toilet from flushing as it should. Without a vent pipe in place, trapped air will act like a clog in the toilet drain, and it may keep water and waste from flushing all the way down. That’s why you can’t have a clogged vent line in your toilet. You simply won’t be able to flush and that’s a whole another problem to think about.

3. To keep the water level constant

There’s always water in the toilet bowl because it seals off the sewer gas. But to be effective, the water level must be constant. Without proper venting in place, that balance will be disrupted, and the sewer gas will leak into your bathroom and possibly all over your home. It means that your toilet will have that nasty smell all the time, which is also what happens if you have a clogged plumbing vent.

How to Vent a Toilet the Proper Way

4 ways to vent a toilet

There are a lot of considerations to venting a toilet, and it is important that you come to this task prepared. First, you must know what drainage pipe sizes you are dealing with and how they will fit into the floor area of the toilet. You should also know what local regulations are in your city when it comes to residential plumbing.

If you got all of those figured out, then you should be ready for the toilet venting project. Listed below are the different ways how to vent a toilet. Read through each of them and select the method that works for you best. Seek guidance from a professional plumber if necessary. Doing this right the first time is essential.

1. Straight Vent

The most common vent configuration for toilets is one where the drain pipe stretches horizontally. It’s configured that way for ease of waste and water delivery into the sewer line. If this is how your toilet is configured, then you’ll have to vent it the opposite way. By that, it means you’ll have to go up the roof for air release. Plumbers call this the roof vent system.

For this, you’ll need wye fittings and tee sanitary drain pipes. Connecting these two parts the right way will allow you to line two drains leading in different directions. One of them goes down the water sewer line while the other goes up the roof. Proper planning is key to do this venting system method right.

2. Under the Toilet Vent

It is also possible to have the vent under the toilet. Here, the vent is placed on the waste pipe, just before it gets to the turning point. For this method, you’ll need reducing wyes for proper attachment. The wye will let you change the angle of the vent pipe so it can detach from the toilet drain pipe as needed.

3. The Wye and Street Elbow Vent

Another way to create a toilet vent is to connect a wye to the street elbow. First, connect a wye horizontally to an outlet pipe. Then run the street elbow 45 degrees from the wye. This configuration allows the vent to be positioned vertically, which makes it ideal for in-wall installation. You may use this for sidewall installation if so desired.

4. Wet Vent

Wet venting is another popular method to vent toilets these days. Here, you only need to use one pipe for transferring air and waste. You just need a wide enough pipe, around two inches in diameter, to allow air and water to pass through easily. 

The wet venting method may also connect to other fixtures in your bathroom, such as the sink and shower. All you need to do is create a common point for all. It is possible to use any sink drains for this purpose. Simply attach the tee pipe to it and you should be all set.

One reason why wet venting is popular is that it saves space. This method is recommended for small bathrooms as you don’t need to create separate vents for each plumbing fixture. The idea is to get the entrance elbow to face where the water flows while having its outlet going up opposite the line to where the waste go. For as long as there is no clogged vent pipe around, this method will work flawlessly for you. 

What to Do if Your Toilet Doesn’t Have a Vent

It is possible to vent your toilet using valves that can admit air. In fact, this is a popular method of venting toilets, although it is quite a bit controversial too. The air admittance valve used in toilets allows for reducing the negative pressure in waste disposal. These valves work by releasing the pipe’s air pressure. An air admittance valve doesn’t rely on solely gravity but may also rise with the water that enters the plumbing system.

This installation of an air admittance valve should not be done if your city doesn’t allow its use according to the local building code. Be very careful when using this method as it is not accepted in all countries. Better check the International Plumbing Code first as it may have some information that you’ll be able to use.

Some plumbers even refer to these valves as the cheater valves because they make venting very easy for non-vented toilets. Even so, don’t cheat the local city plumbing codes if you are not allowed to. The confusion of using this method lies in the absence of a uniform plumbing code in most countries. Hopefully, that would change soon.

With that aside, this method works. What is so great about these air admittance valves is that they don’t require too much space to install. They work by admitting air into the plumbing system and looking for the zones where there is low pressure. Once it finds that, it opens the seal. These mechanical valves allow air to enter the fixture drain line quite easily.

Once the pressure is restored, it closes the seal mechanically using gravity. It is how sewer gases won’t get in the valves and out into the open. If there the balance in the pressure inside the plumbing pipe is maintained, flushing the toilet will work as usual. These air admittance valves will stay in their original positions until the pressure drops again and start to activate.

While these valves are considered illegal in some places, they are quite beneficial. If its installation is allowed where you are located, then you may consider using them as they can greatly reduce the installation cost of drainage systems. Aesthetic-wise, people who don’t want to make a hole in their roofs will prefer this type of vent piping.

What to Consider When Venting Toilets

What to Consider When Venting Toilets

As mentioned earlier, there are many ways to vent your toilet. You may choose any one of the four widely acceptable steps described above or if you can, settle for air admittance valves. Just be sure that you use a method that would work for your drain and toilet as the comfort of your family lies on it.

Some of the major considerations when choosing the right method are the length of the waste pipe and drainage system; air vent height; sink drain and toilet distance; and air admittance valve availability. If you can’t decide which venting method is ideal after evaluating all of these, don’t hesitate to seek the help of a licensed plumber.

Always keep in mind that toilets won’t work if it doesn’t have proper venting. Do consider all your options and choose a method that perfectly matches your house’s plumbing system. The right venting method is one that’s easy to install, suits your budget, and works for a long time.

A consultation with a plumber is necessary before and after the vent installation. Doing so will prevent you from having a blocked vent at any time. Also, you should contact the pros for any plumbing problem you encounter while installing these vents. They will surely help you make some crucial decisions along the way. They can even tell you what size of PVC pipe drain you will need and how to install a Studor vent. Some plumbers are even qualified to vent your water heater and air conditioning system if needed. So, whether it is an air conditioner or a venting system that you are having trouble with, don’t hesitate to contact these experts. You will surely need all the help that you can get.

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