05-13 Vents

Question: 05-13Code Section: 7Date:OBC 2006 Reference:

Question: This is a four part question and all are not related. However:

1. what is the minimum size vent required for a manhole that is within a building, please state the code section?

2. 7.5.5.3.(1)(c) and (2) talks about cumulative change. The question pertains to a fixture drain with 3 45 degree bends that connects to a continuous waste and vent through a Y fitting.  Is the cumulative change of direction 135 or 180 ?  It would appear from the Appendix that the branch of the fitting is not included in the measurement yet it would have a bearing on the developed length of the fixture drain.  Please explain as best you can so that I may further explain to the class (Intermediate Plumbing Course)

3. What does a bathroom group consist of?

4. The definition of storey in Part 7 is different than Part 1 and when sizing vertical stacks, the students questioned if there was any relation to stack height versus storey?  Ie. a 10 storey building with plumbing only on the top 4 floors, is the stack height 10 storeys or 4 storeys?

Interpretation: (On. Reg. 403/97) 1. The minimum size vent is 3 inches based on past performance and Ontario Regulation 647/80, Section 2.7
2. The cumulative change of direction is 135 degrees.  The wye branch is not included.  See 7.5.5.3.(1)(c).
3. See Appendix Notes A-7.4.9.3.  A bathroom is considered to consist of one water closet, one lavatory and one bathtub (with or without shower head) or shower stall.
4. 10 storeys.  See the definition in Part 7.