Vent through a porch roof
What's wrong here?
- The vent terminal is within 10 ft of an openable window and not 3 ft above it
- The vent does not extend far enough above the roof for Minnesota
- A rubber boot is not an approved flashing for a plumbing vent
- Nothing. This installation is compliant
Show the answer and the code reference
The answer
The vent terminal is only about 4 ft from an openable window and sits below it, so it is neither 10 ft away nor 3 ft above the window.
Correct choice: 1. The vent terminal is within 10 ft of an openable window and not 3 ft above it
UPC 906.2 requires each vent terminal to be not less than 10 ft from, or not less than 3 ft above, any openable window, door, opening, air intake or vent shaft. An open vent breathes sewer gas, and here it sits a few feet from a second-story window that is standing partly open. Measure the horizontal distance from the terminal to the nearest edge of the opening; if it is under 10 ft, the top of the vent must be at least 3 ft higher than the top of the opening.
How to fix it
Relocate the vent so it comes through the roof at least 10 ft from the window, or offset it in the attic and carry it up through the upper roof so it ends at least 3 ft above the top of the window. Wherever it ends, keep it at least 12 in. above the roof for Minnesota and at least 1 ft from any wall.
Code references
UPC 2018 906.2 — Vent Termination Clearance
Each vent pipe or stack shall terminate not less than 10 ft from, or not less than 3 ft above, an openable window, door, opening, air intake or vent shaft, and not less than 3 ft in every direction from a lot line (alley and street excepted).
Drills citing 906.2UPC 2018 906.1 — Roof Termination
Each vent pipe or stack extends through its flashing and terminates vertically not less than 6 in. above the roof and not less than 1 ft from a vertical surface. Minnesota is reported to raise the height above the roof to 12 in.
Drills citing 906.1
Minnesota
Minnesota adopts the 2018 Uniform Plumbing Code with Minnesota amendments as the Minnesota Plumbing Code (Minn. Rules ch. 4714, effective Dec. 17, 2021). No Minnesota amendment to the 906.2 clearance from windows and openings is known. Search-result excerpts indicate Minnesota amends other parts of UPC 906 (apparently in part 4714.0906), including a 12 in. minimum height above the roof, but that text could not be read; check ch. 4714 before relying on it. A terminal a few feet from an openable window and below it fails any version of the clearance rule.
About the Minnesota Plumbing CodeCitation under review. Confirm the 2018 UPC headings for 906.1 ('Roof Termination') and 906.2 ('Vent Termination Clearance'), and what Minn. Rules ch. 4714 (apparently part 4714.0906) changes in UPC 906. Search excerpts mention a 12 in. height above the roof in 906.1 and changes to 906.3 and 906.7; confirm that 906.2 is unamended. The answer holds under any of these versions because the terminal is below the window and only a few feet from it.
Why the other choices are wrong
- The vent does not extend far enough above the roof for Minnesota. The pipe stands well over a foot above the shingles. That clears the 6 in. in UPC 906.1 and the 12 in. Minnesota is reported to require, so height above the roof is not the problem.
- A rubber boot is not an approved flashing for a plumbing vent. UPC 906.1 only requires the vent to extend through its flashing; a pipe boot like this one is a common, accepted vent flashing.
- Nothing. This installation is compliant. Sewer gas from the open terminal is a few feet from a window that opens; UPC 906.2 requires 10 ft of separation or a terminal at least 3 ft above the opening.