On a sink that would be either the rim or overflow hole.
Vent pipe distance above roof.
Vent pipes shall terminate not less than 6 inches above the roof measured from the highest point where the vent intersects the roof.
The re vent is the only exception since it runs horizontally.
Window or fresh air intake.
If the pipe is farther than 10 feet from the roof peak it must be 2 feet above the highest point of the roof within 10 feet.
A note on the main drain.
Above the roof plumbing vent height.
However it needs to be at least six inches above your fixture s flood level to keep from getting wet.
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.
The vent stack is the pipe leading to the main roof vent.
When builders look only at the table without reading the text they find that a 2 inch diameter drain can run a maximum distance of 8 feet to the vent.
It channels the exhaust gases to the vent and helps maintain proper atmospheric pressure in the waste system.
Where a roof is used for any purpose other than weather protection vents shall extend at least 7 feet above the roof and shall be properly supported.
The epa and other guidelines somewhat follow the standard codes for plumbing vent pipes which generally are vented above the buildings roof.
New york state just raised plumbing vent pipe code from 12 inches to 18 inches above the roof and at least 10 feet horizontal distance from any opening to the building i e.
Its drainage and vent functions are actually two systems.
Why plumbing air vents are important.
In other words the highest point within a 10 foot circle of the pipe.