Do ALL drains need venting?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by krosspen, Aug 15, 2014.

  1. krosspen

    krosspen New Member

    Messages:
    5
    Location:
    Wisconsin
    I'm putting in bathroom #2 upstairs. A freind who knows plumbing better than I tells me I don't need to vent a shower with a 2" drain. Is that so?
  2. Terry

    Terry Administrator Staff Member

    Messages:
    15,289
    Location:
    Bothell, Washington
    That is not correct. The shower needs venting.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    To amplify what Terry said, each fixture needs a trap and a vent, but there's sometimes a lot more than one way to accomplish it. In a bathroom group, if you do it right, you can do what is called 'wet venting'. If it is done right, each trap still is getting vented, but there may not be an individual vent line one each of them. THe order, distances, pipe sizes, all play into whether that is possible, but the best way is often to just vent each individually for maximum flexibility later on if you should decide to move things around.
  4. krosspen

    krosspen New Member

    Messages:
    5
    Location:
    Wisconsin
    Thanks guys, very much. Since we don't know all the factors that allow us not to have a dedicated vent, Im opting to vent the sink and shower (in one) . The fella I'm hiring who is unfamiliar with it must have had all the other things factored in to the plans back when he was doing plumbing.... ten years ago. ONE MORE question.... I see a lot of toilets not vented. We're about 7 or 8 feet from the stack. I'd love to NOT vent the toilet, any advise?
  5. wjcandee

    wjcandee Wise One

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    New York, NY
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    A toilet can work without a vent. The toilet's trap is IN the toilet, and that is open to the room on top. It gets more complicated when the trap of something else in below the floor or doesn't have its own vent. IF there is anything else on that line before a vented fixture, though, it can cause problems.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,026
    Location:
    Cave Creek, Arizona
    There are so many variables when it comes to drains, vents, and traps, that each situation has to be addressed individually. And, you CANNOT "put a bathroom on the second floor" just because that is where the downstairs pipe is.
  8. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,265
    Location:
    Maine
    Whether you vent the toilet or not depends on who's code you are required to follow. Though the IPC lists water closet to vent distance as unlimited, there still needs to be a vent on the system somewhere. You can never use vents from floors below to receive the discharge from fixtures above.
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