Its drainage and vent functions are actually two systems.
Roof vent pipe height.
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.
A note on the main drain.
In other words the highest point within a 10 foot circle of the pipe.
Above the roof plumbing vent height.
The regulations were changed from the days that you needed those 1m or so long pipes jutting from your roof.
Why plumbing air vents are important.
Does anyone know what legal height requirements there are for vent pipes from memory i m pretty sure that it must only be a minimum of 300mm above the gutters that s to ensure storm water does not get into the sewer system.
Vents exceeding 40 feet 12 192 mm in developed length shall be increased by one nominal pipe size for the entire developed length of the vent pipe.
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.
The required size of the drain shall be determined in accordance with table 710 1 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.
A vent terminal and depending if the roof is strictly for weather protection it terminates about 24 above the roof.
Vent pipes shall not be less than 1 1 4 inches 32 mm in diameter.
However it needs to be at least six inches above your fixture s flood level to keep from getting wet.
On a sink that would be either the rim or overflow hole.
The re vent is the only exception since it runs horizontally.
If the roof area is for people then it is 7 ft above the roofing surface.