Important Plumbing Code Information about Vents and Venting

When working with plumbing, it's extremely important that you understand the plumbing code in your area. These codes are designed as a way to make sure that plumbing is safe, and doesn't endanger property or lives.

Deciphering Plumbing Codes

Deciphering the information in plumbing codes can be very confusing since every state has a different set of codes. To make matters even more complicated, the plumbing codes often change without warning. That's why you need to get up to date as quickly as possible.

Plumbing codes are there for a reason, and this is normally to protect our health and to make sure that plumbing systems work the best they can.

Installing Toilets

When installing new toilets, the uniform plumbing codes stipulate that the pipe must be vented. Normally, this is done by venting the pipe at the top. The pipe will often continue a short way past the roof line. It it is not possible to go through the roof some states allow the use of Air Access Valves, or side mounted vents.

The uniform plumbing code stipulates that at least a 2 inch opening for the vent is required.

Understanding Your Plumbing System

There are three main components of any plumbing system in any house. These are the drain lines, waste water pipes, and vents. The toilets are not connected to the same drains as the sinks and showers. This could cause raw sewage to come back up through the sinks if there was ever a blockage.

Vents are required for all drains, and there are good reasons for this. The most important is to prevent a nasty build up of gasses or bacteria. The drains will all connect into the sewer. If the gasses can come up through the sink it would not be very healthy. The vents are designed to get rid of the gasses and bacteria before they affect the inside of your home.

The vents also serve another very useful purpose: to deal with the pressure in the pipes. The vents allow the air to push the waste water down and out of the pipes. If it wasn't for this vent it would be quite easy for the water to push back into your toilet or sink.


All vents will also have a trap, which is normally a U or S shaped piece of pipe. This will prevent the gasses from entering the house, because the easiest route will be straight up and out through the vent at the top of the building.


The main reason for any plumbing code is to improve your health. They may seem like a nuisance at times, but they are worthwhile following. After all, who would want to smell sewer gas in their bathroom?