How to handle an exposed kitchen sink vent line after the removal of the soffit.

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Last updated on December 8, 2022


My husband & I are DIYers. We bought a 70’s ranch and have gutted the kitchen, including removing the old soffits. Our new cabinets are 30″ and we wanted the top open for decor and lighting, but ran into a kitchen sink vent pipe that was hidden in the soffit. It sticks out about 3-4 inches into the room. It has two 90 degree turns, from inside the wall

Out about 3-4 inches, then turns again up into the ceiling and vented out through the roof. We cannot just run straight up through the walls as we run into the roof headers. One thought we had was to turn it around, run it through the outside eave into the attic and then bring it back in to connect with the original outside vent. Sounds complicated but we don’t know what else to do.  Any suggestions?


We often run into concealed kitchen sink vent lines when we remove the soffits.
To reroute these pipes can be difficult.  When the pipes are concealed in the walls, you must be careful not to over-bore the hole, especially on load bearing walls.  If the wall is load bearing, you should double up the studs prior to drilling the hole for the pipe.

If you cannot reroute the vent line, you can consider using an air-admittance valve.  You can learn more about these devices at this web site:  These valves take the place of vent lines and are often installed in the sink base cabinet.  They can be purchased at most hardware stores or home centers.   Most model codes allow their use, however, there are some municipalities that do not allow them.  You will have to check with your local code’s department to see if they are allowed in your area.
After you visit the web site, you’ll see that they are a fairly simple way to handle your predicament.  Good luck on your remodeling project.