BCAB #1641 - Plumbing Vent Grade Sentence 7.5.6.1.(1), Sentence 7.5.6.2.(1)

February 27, 2008

BCAB #1641

Re: Plumbing Vent Grade Sentence 7.5.6.1.(1), Sentence 7.5.6.2.(1)

Project Description

Two 1 1/2” branch vents have been installed in the attic space of a single family dwelling. The vents are flat with no grade, and are supported on roof trusses.

Reason for Appeal

Sentence 7.5.6.1.(1) requires every vent pipe to be installed without depressions which water can collect.

Sentence 7.5.6.2.(1) requires every vent pipe to be installed in a nominally vertical position where it is practical to do so.

Appellant’s Position

The appellant contends that grading of a vent pipe ¼” per foot, as requested by the Building Official, is not a Building Code requirement and that a flat vent pipe does not have depressions which water can collect.

Building Official's Position
The Building Official considers the vent pipe must be installed in a nominally vertical position. Further, there is the possibility that water could collect in a horizontal vent. Appendix diagram A-7.5.8.  indicates nominally horizontal sections of venting systems grading back to the drain.

Appeal Board Decision #1641

It is the determination of the Board that a vent pipe is not required to be graded, but cannot have any depressions that moisture could accumulate. The Board considers that Sentence 7.5.6.2.(1) is not applicable to this appeal as it relates to the connection of a vent pipe to a drain.

George Humphrey, Chair