Wet venting "by the code"

Discussion in 'IPC Plumbing Code Questions' started by josef, Jul 8, 2014.

  1. josef

    josef New Member

    Messages:
    5
    Location:
    atlanta
    First let me say, it has been a while since I've read the IPC 2009 or 2012, and I am not a plumber, nor am I involved in trying to plumb anything at the moment.

    So, as a consultant for investors and banks, part of my daily tasks are to inspect construction drawings (typically on 3-6 story apartment buildings), make sure the Scope of Work for the building meets the loan amount, and identify discrepancies which may cause Change Orders which would delay the project and/or add costs to the job. In no way am I responsible for means and methods, nor am I even on the design team. Most of my time is spent in the Architectural and Structural sections.

    However, I seem to recall something about wet venting only being allowed for bathroom stacks, and I constantly see kitchen sinks with dishwashers and washing machines connecting to risers running straight through the roof and each fixture tied into the riser at each floor. When the sinks are in islands and the horizontal branch drain is long enough, I'll see the standard AAV, but otherwise, these fixtures all seem to be wet vented to me.

    Now most construction issues end up being caught in field, and the rare issue I notice that the contractor does not fix, especially after city inspection approval, isn't going to be fixed just because I bring it up in a report. However, for my own purposes/peace of mind, could someone tell me when exactly different fixtures are allowed to be wet vented per IPC 2009/2012 (the two variants in the region I cover) and how much you would charge (round number) per apt unit in a change order if you knew you'd have to add venting to a riser during construction to a building that didn't show it in the plans?

    Thank you very much.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    wet venting is only allowed for fixtures on the same floor/level, NOT, for example, for sinks on different floors. When they are connected to a single pipe, that is a "Philadelphia single stack" and is only approved for THAT city and only when designed by a mechanical engineer. The IPC is working to adopt it, but as far as I know has not done so yet, and when it is, it will not be something the plumber can just "decide to do it". IF the venting is NOT n place during the original construction, it normally requires that the entire stack be discarded and the new one installed properly. It is NOT something that can be easily, or cheaply, retrofitted.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    As for AAVs in a multistory stack, they are completey ineffective because those stacks are subjected to positive pressures which an AAV cannot do anything about.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,537
    Location:
    Cave Creek, Arizona
    As for AAVs in a multistory stack, they are completey ineffective because those stacks are subjected to positive pressures which an AAV cannot do anything about.
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