| Question: 13-22 | Code Section: 7 | Date: 22 November 2013 | OBC 2012 Reference: |
Question Submitted: I have a contractor for an addition that removed a portion of my old vent stack that was cast iron.
The questions I have are:
1) The contractor rather than using ABS used an insulated flexible duct to make a curve in the duct and then to ABS to penetrate the roof, is this to code?
2) The penetration through the roof is actually 5 feet from a wall that was added as part of the addition, this wall at its peak is approximately 8 feet above the newly installed penetration of the vent stack. Is this position to code?
3) As we live in Ottawa I am worried that the proximity to the wall will allow for snow build up above the vent stack thus blocking the stack, Should I be worried?
4) Should the stack be vented through the roof (above the wall that added as stated above) that is higher than its newly installed position?
5) Also if there is a greater positive pressure at the top of the vent stack because of its position and proximity to the wall is that not an issue to be concerned about?
Interpretation: There are a lot of questions here that all deal with essentially 2 sections of the code.
Question 1) refers to pipe materials. Since Insulated flexible duct is not listed as an acceptable material for use in a plumbing system in 7.2.5. (Non-Metallic Pipe and Fittings) or 7.2.6. (Ferrus Pipe and Fittings), they cannot be used.
Questions 2) through 5) ask about the termination point of the vent to open air. The code reference dealing with vent terminals is 7.5.6.5, listed in it are only location restrictions if openable windows or doors are within a certain proximity. Since it is not mentioned in the question that this condition exists, there appears to be no code reference restricting this installation. As for the installed height above the roof, the code lists only a minimum 150mm above the roof to prevent entry of roof drainage.