Plumbing Vent Pipe Height Above Roof

You are letting air into the plumbing system of the house.

Plumbing vent pipe height above roof. Upc i 906 1 and 906 2. Vent pipes should extend to outdoors above the building roof and should terminate vertically not less than 6 above the roof surface nor more than 24 and must be at least 12 from any vertical surface such as a nearby sidewall. I have a main vent and a sink vent and both are only 6 high above the roof. I am sure the plumber put it at that height for the inspector.

However it needs to be at least six inches above your fixture s flood level to keep from getting wet. But it is on the edge of the roof so that should not be a problem. The slope is about 4 high for every 12 horizontal. You must also consider the snow line so the pipe does not get covered.

A vent stack is not like a chimney which requires 2 higher than any roof within 10. The vent is supposed to be 10 away or 2 above any window. Above the roof plumbing vent height. The re vent is the only exception since it runs horizontally.

The 6 you describe should be just fine. All open vent pipes that extend through a roof shall be terminated at least 6 inches 152 mm above the roof and not less than 2 inches 51 mm above the invert of the emergency overflow except that where a roof is to be used for any purpose other than weather protection the vent extensions shall be run at least 7 feet 2134 mm above the roof. On a sink that would be either the rim or overflow hole. Open vent pipes that extend through a roof shall be terminated at least 6 inches 152 mm above the roof or 6 inches 152 mm above the anticipated snow accumulation whichever is greater except that where a roof is to be used for any purpose other than weather protection the vent extension shall be run at least 7 feet 2134 mm above the roof.

You should be able to cut that vent shorter but stay above the roof line. A note on the main drain.