What Are Sewer Vent Pipes For?


For the plumbing to work correctly in any house, the pipes require a down-slope to drain sewage from sinks, showers and toilets. The plumbing also needs sewer vent pipes tied into the drainage pipes.


  • As sinks, showers or toilets empty, gravity helps drain the waste downward to a main sewer pipe that carries it from the house to a regional water treatment plant. Sewer vent pipes attach to the plumbing at the house's lowest level and extend upward through the roof to a capped or uncapped pipe.


  • Vent pipes let air into the plumbing system, preventing vacuum formation which permits trouble-free sewage drainage. Air also begins the sewage decomposition process, which produces sewer gas that needs proper ventilation to prevent build-up to gas leakage into the house. Vent pipes also carry sewer gas up to the rooftop, allowing it to escape and preventing build-up in the plumbing.


  • The smell of sewer gas inside indicates a damaged vent stack or problem in the plumbing that allows gas into the house (e.g. a poorly sealed toilet or a p-trap). It may be necessary to have a plumber perform a smoky test to locate the problem and determine how to repair it.

Related Searches


  • Photo Credit sewer image by blacklight from Fotolia.com
Promoted By Zergnet



You May Also Like

  • How to Install a Sewage Basin

    Whether you are installing a toilet, washer, dishwasher or a sink, a sewage basin may be necessary. Sewage basins collect the refuse...

  • How to Vent a Sewage Pump

    A sewage ejector pump is used when there are plumbing fixtures, such as toilets, below the public or private sewer line. Since...

  • What Is Sewer Gas & Can It Blow up a House?

    In the early 20th century, sewer gas was greatly feared by homeowners, many of whom believed it could introduce germs into the...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!