My shower and washing machine drain need a vent pipe. Should I put the vent downstream from both of them or in between them? -Deb

Hi Deb,
Depending on the distance between the drain pipes for the shower and washing machine, you may be able to install a single vent at the drain further downstream to serve them both.

The maximum distance recommended between two drain pipes for them to share a vent is 3½’ for a 1½” drain and 5’ for a 2” drain pipe. If they’re further away than that, each should have their own vent, though the two vents can join together before going through the roof.

If your codes allow, you may be able to avoid running another vent stack through the roof by attaching a one way vent known as an air admittance valve on the drain line. This allows air in while preventing sewer gases from coming out.

Good luck with your project,


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Danny Lipford

Danny Lipford


Danny Lipford is a home improvement expert and television personality who started his remodeling business, Lipford Construction, at the age of 21 in Mobile, Alabama. He gained national recognition as the host of the nationally syndicated television show, Today's Homeowner with Danny Lipford, which started as a small cable show in Mobile. Danny's expertise in home improvement has also led him to be a contributor to popular magazines and websites and the go-to source for advice on everything related to the home. He has made over 200 national television appearances and served as the home improvement expert for CBS's The Early Show and The Weather Channel for over a decade. Danny is also the founder of 3 Echoes Content Studio,, and Checking In With Chelsea, a décor and lifestyle blog.

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