It also allows fresh air into the plumbing system to help water flow smoothly through the drain.
Plumbing vent pipe height above roof.
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.
A vent stack is not like a chimney which requires 2 higher than any roof within 10.
Above the roof plumbing vent height.
The re vent is the only exception since it runs horizontally.
The slope is about 4 high for every 12 horizontal.
However it needs to be at least six inches above your fixture s flood level to keep from getting wet.
Just as drain pipes remove water and waste from your home the plumbing vent pipe also known as a plumbing air vent removes gas and odors.
Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than 6 inches 152 mm above the roof nor less than 1 foot 305 mm from a vertical surface.
The 6 you describe should be just fine.
All open vent pipes that extend through a roof shall be terminated at least number typically 6 inches mm above the roof 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.
You are letting air into the plumbing system of the house.
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.
The plumbing vent also known as a vent stack helps regulate the air pressure in your plumbing system.
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.