Plumbing Vent Pipe Code

The plumbing drain system in a home has to “breathe” in air so it can flow smoothly. But the vent piping can also emit noxious sewer gas, so it is necessary to terminate the pipes in a safe location where the sewer gas will not come back into the house.

    A vent through the roof must terminate a minimum of 6 inches above the roof surface or 6 inches above any anticipated snow accumulation. Vents through walls have to terminate at least 10 feet above the ground or adjacent surface, but cannot be below a vented soffit. Here’s one example of what not to do.

When a vent terminates directly below a window, door, or air intake, it must be at least 4 feet under it or 3 feet above it, unless the vent is 10 feet or more away. Vents are also required to be at least 7 feet above a roof when it is also used as a walking surface.

Vent terminations near any air intakes on a roof must be a minimum of 3 feet above the intake opening, or at least 10 feet away.

    Vents terminating at an air admittance valve in an attic must be a minimum of 6 inches above the insulation.

    Side wall vents are required to be protected from entry of birds or rodents, usually by a coarse mesh screen.  Also, the use of vent terminations for anything other than vent termination is prohibited.

    These standards are at Section “P3103 - Vent Terminals” of the Residential Edition of the Florida Building Code (FBC) and the International Residential Code (FBC). 

    Also see our blog post How many plumbing vents through the roof are required by code?

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Here’s links to a collection of our other blog posts about PLUMBING:

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Why is there sand in the bottom of my toilet tank?  

• What causes a gurgling sound when a bathtub or sink drains? 

• Are drop-in toilet bowl cleaner tablets safe? 

• What can I add to my septic tank to help it work better?

• What are the code requirements for layout of drain piping under sinks? 

• Why is there mold inside my toilet tank?  

• What are the pros and cons of a wall-mounted toilet?

• Which plumbing fixtures require water shut off valves in a home? 

• How can I tell if a house is connected to a septic tank system or sewer?

• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

• Why is a backflow preventer required on lawn sprinkler systems? 

• How can I locate my septic tank? 

• Is a hot water faucet handle required to be on the left? 

• Can you live in a house while the plumbing is being replaced? 

• Why is the European-style bottle trap not approved by the plumbing codes in the U.S.? 

• Why can't PVC be used for water pipe inside a house? 

• What are the common problems to look for when the plumbing has been replaced in a house? 

• What's that powdery crust on the pipe connections at the water heater? 

• How can I tell what type of plumbing pipe I have? 

• My water bill went way up last month. How do I look for a leak?

• Why does the water have a rotten-egg smell in some empty houses? 

• What is an "S-Trap" under my sink? Why is it a problem? 

• Where is the septic tank? Are you going to inspect it? 

• Does a home inspector check the plumbing under the floor slab?

• Is it alright to disconnect the washing machine drain from the septic tank and divert it to the ground in the yard?

      Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.