I am sure the plumber put it at that height for the inspector.
Vent pipe height above roof.
However it needs to be at least six inches above your fixture s flood level to keep from getting wet.
Upc i 906 1 and 906 2.
Single wall metal pipe shall extend at least 2 feet 610 mm above the highest point where it passes through a roof of a building and at least 2 feet 610 mm higher than any portion of a building within a horizontal distance of 10 feet 3048 mm.
This may seem suitable since the only purpose for the stack is to provide air and expel sewer gases.
You should be able to cut that vent shorter but stay above the roof line.
For those stinky vents consider installing odor hog vent caps see image on the roof vents.
We install our roof vents 6 to 8 inches above the roof line.
Above the roof plumbing vent height.
You must also consider the snow line so the pipe does not get covered.
From any vertical surface the soil pipe also known as the vent stack or stack pipe provides air for the 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.
The re vent is the only exception since it runs horizontally.
You are close to your eave and you find that your measurement is 18 feet from peak to penetration on a 4 12 pitch see figure 3.
A note on the main drain.
If the roof area is for people then it is 7 ft above the roofing surface.
A vent terminal and depending if the roof is strictly for weather protection it terminates about 24 above the roof.
Above the roof nor less than one 1 foot.
For 18 feet of run you would have a rise of 72 inches.
Let s look at a couple of examples.
The vent is supposed to be 10 away or 2 above any window.
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.
Many people mistakenly think that the pipe always has to be 2 feet above the roof peak.