IPC Vent Grade

Discussion in 'IPC Plumbing Code Questions' started by frodo, Mar 7, 2019.

  1. frodo

    frodo New Member

    Joined:
    Jun 29, 2013
    Occupation:
    plumber
    Location:
    Mississippi
    Is the interpretation of the IPC code saying that A and B are acceptable?
    Where as the UPC clearly states only B is allowed

    vent.png
     
  2. Sylvan

    Sylvan Still learning

    Joined:
    Sep 23, 2004
    Occupation:
    plumbing- - fire suppression
    Location:
    New York
    I vent up from the fixture being served Picture B

    Picture A I would not find acceptable
     
    frodo likes this.
  3. Sponsor

    Sponsor Paid Advertisement

     
    frodo likes this.
  4. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    I've always done B
    Grade back to the fixture it serves.
     
    frodo likes this.
  5. frodo

    frodo New Member

    Joined:
    Jun 29, 2013
    Occupation:
    plumber
    Location:
    Mississippi
    Thanks for the answer
    I do not find picture A as acceptable either,
    BUT, am being told by IPC plumbers [I am a upc plumber]
    that the grade back to the fixture does not matter
    in this diagram, this would not be acceptable.[upc] i would sleeve that duct in a heat beat. lol
    2.jpg
     
  6. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    Frodo, your interpretation makes sense to me. I could see why IPC would logically find either OK. I am not a plumber.

    What was the "i would sleeve that duct..." part? Accidental paste?
     
    frodo likes this.
  7. frodo

    frodo New Member

    Joined:
    Jun 29, 2013
    Occupation:
    plumber
    Location:
    Mississippi

    sleeve (1).png

    Terry... I know what you have always done, same as me, drain back to the fixture it serves
    What I am looking for is the precise interpretation to the IPC vent grade definition.
    the way it is worded, You can install a vent any way you want, as long as it has fall.

    The IPC plumbers i am running into are saying that "AIR DONT CARE"
    which is technically true, it just makes the work look like total ass
     
  8. Stuff

    Stuff Active Member

    Joined:
    Mar 7, 2013
    Location:
    Pennsylvania
    It sounds like the plumbers you are running into have air in their heads. Air actually does care. Warm air rises. Without the slope to the fixture gasses might get trapped. Logically you also plan for the possibility of rainwater and condensation. Does any other liquid get in a dry vent above flood level?

    If the grade slopes down to the vent then you are using the vent as a drain. It will work but not code in most situations.

    Note your sag in red would act as a trap. So if you tested the system by filling with water you would have issues starting on day 1.
     
    frodo likes this.
  9. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I think the logic is that with A, the only water heading toward the vent is vent water... which would only be condensation. Just as with the rain and other condensation, the vent water eventually hits a drain.
     
  10. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    They may be right as far as it working. Sort of like a kitchen Island vent in that both sides can drain down. I'm assuming the low part would drain back down the other vent with the tee or wye pointing downward.
    Let us know how that goes.

    [​IMG]
     
    Last edited: Mar 8, 2019
    frodo likes this.
  11. frodo

    frodo New Member

    Joined:
    Jun 29, 2013
    Occupation:
    plumber
    Location:
    Mississippi
Similar Threads: Vent Grade
Forum Title Date
IPC Plumbing Code Questions Plumbing/Venting for half Bathroom Yesterday at 8:05 PM
IPC Plumbing Code Questions Foot vent and island venting Mar 15, 2019
IPC Plumbing Code Questions Wet Venting confusion Sep 5, 2018
IPC Plumbing Code Questions Why is loop venting generally prohibited? Jul 18, 2018
IPC Plumbing Code Questions Non vented plumbing in Costa Rica Nov 2, 2017

Share This Page