Which Vent Size for Toilet Sink and Shower Do You Need?

vent size for toilet sink and showerYou may know that the vent is connected with the drain (both toilet and shower drain). It is also true that the toilet sink and shower do not have much space that you can use any of the vent sizes for your toilet sink and shower.

So, which vent size for toilet sink and shower do you need? According to my experience, the most commonly assembled 2-inch PVC vent is the best option for a toilet sink, and the shower/tub vent size is 1.5-inches. If you want to use only one size, you can use a 1.5-inch size vent without facing a single problem.

It is the standard measurement of a vent size for the toilet sink and shower. The drain system of nearly all the toilet and shower/tubs is the same. I strongly believe that the following information helps you a lot to get detailed information about this matter.

Vent Size for Toilet Sink and Shower

Typically, vents are used in the drain of the toilet and shower/tub. Most toilet and shower plumbers think that the toilet and shower vent size depends on fixtures because more fixtures need more size vents.

But, the standard vent size for the toilet is 2″ PVC pipe, which helps you to use the vent in your toilet drain system comfortably. On the other hand, the shower or tub needs a 1.5″ standard size vent, which is truly the best option for shower or tub.

According to my experience, the 1.5″ size vent is perfectly designed for toilet and shower drain. The 1.5″ vent size is perfect for toilet and shower because the size is easily connected with the drain and stable to use.

How to Vent a Toilet Sink and Shower?

How to Vent a Toilet Sink and Shower.

No bathroom construction full-fill until the toilet and shower ventilation. So, what can you do to vent a toilet sink and shower? Well, you can check out each of the points so that you can vent your bathroom toilet sink and shower yourself.

  1. First, you need to choose the right size vent pipe for the toilet and the shower or tub. I used a 1.5″ PVC pipe.
  2. After that, you should cut the pipe with your toilet drain size so it can connect perfectly.
  3. Now, it is time to connect the PVC pipe to the toilet and shower sink. Check out that it is securely connected; otherwise, it may affect the draining systems.

The connection should be strong enough to pass out the air and water pressure properly. When you flush the toilet, the air creates pressure to remove and down the waste. Do you feel hesitant to vent your toilet sink and shower? Let me know your feelings.

Can You Vent a Toilet out the Wall?

Can You Vent a Toilet out the Wall

It is hard to do but still possible to vent a toilet out the wall. You can easily pass the vent through the wall instead though the wall outside of the toilet. Note that it is a hard task, and if you feel that you don’t have any experience in venting a toilet, you can avoid it and hire a plumber.

Moreover, the toilet vent should have come in the right size, and of course, you should not go up to a 2-inch PVC pipe for venting a toilet out the wall.

FAQs (Frequently Ask Questions)

Q: Can a toilet shower and sink share a vent?

Answer: A toilet and shower sink easily share a vent when the right size vent comes out. You can share the toilet and shower sink by using a 2-inch PVC pipe. You can simply check out the above 3 points to get a clear concept about this matter.

Q: Does a toilet need a 3-inch vent?

Answer: It depends on the fixtures. If the fixtures come with lots of numbers, you can go for the 3-inch vent. On the other hand, you should not go up to 2-inch vent size because it is hard enough to assemble and also need to use of extra tools.

Q: What size vent is required for a toilet?

Answer: It is recommended to use a 1.5″ to 2″ vent size for a toilet because these two sizes are the most popular for using the toilet drain. But, when the toilet needs lots of fixtures, it would be better for you to go for a 3″ vent size.

Q: What size vent does a shower need?

Answer: Usually, it demands a 2-inch drain pipe or 2″ PVC pipe. It also depends on local requirements. According to a toilet and shower plumber, a 2″ PVC pipe is a solid solution for the shower head.

Q: Can a toilet and shower share the same drain?

Answer: The general toilet and shower share the same drain, and most of the home’s bathroom comes with the same drain because of reducing cost and getting a user-friendly experience. So, you can also use the same drain for the shower and toilet.

Q: What size should my plumbing vent be?

Answer: It depends on the plumbing areas where you want to use it. However, your plumber uses a 1.5″ or 2″ vent for the toilet and shower sink. Your plumber should not go up to 2″ vent size because of several problems.


Vent size is a true factor for toilet and shower sink construction. You or your plumber never avoid the right size vents. However, you can use a 1.5″ to 2″ vent size for the toilet or shower sink without facing any problems. Note that some of the plumbers use a 3″ vent size because of local demands.

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