redundant vent and wet vent

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by lmei007, Aug 5, 2013.

  1. lmei007

    lmei007 Member

    Messages:
    161
    Location:
    Maryland
    Two questions here as shown in the drawing:

    1. Want to remove the red vent to hide pipes and thinking that vent is redundant. is it ok?
    2. is that wet vent valid?

    thanks,

    Attached Files:

  2. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,135
    Location:
    Maine
    If your drawing is accurate the red pipe never should have been there in the first place.
  3. asktom

    asktom Member

    Messages:
    530
    Location:
    Victor, MT
    The wet vent is not legal because it is not all on the same floor. I don't know what code you are under, but the 5' is too long for a 1 1/2" trap arm under the UPC.
  4. lmei007

    lmei007 Member

    Messages:
    161
    Location:
    Maryland
    I think you are right. Plan to add a vent to it.

    The new blue vent has to up to first floor and at least 6" higher than the first floor bath before it connect to the existing vent?

    Attached Files:

    Last edited by a moderator: Aug 5, 2013
  5. asktom

    asktom Member

    Messages:
    530
    Location:
    Victor, MT
    The downstairs vent needs to tie in at least six inches above the top of the bathtub (assuming the tub is the only thing connected to that drain on the first floor). So, you are going to be in the wall on the first floor. If the lavatory is hooked into the tub vent there is another problem.

    The section of tub vent below the that is horizonal below the floor does not meet code, it also needs to be above the top of the tub. If the red pipe really goes up at a 45 then that makes the tub vent legal (but not the basement sink vent). If it is going up at less than a 45 it is no good. 45 or more upright is considered vertical, less than 45 is horizonal. You need vertical until 6" above the fixture.
  6. lmei007

    lmei007 Member

    Messages:
    161
    Location:
    Maryland
    This vent and this main stack only serve the first floor tub and basement sink. No other fixtures connect to them. There is another set of main stack and vent for toilets and first floor sink on another cornor of the room.

    I understand the blue vent is not valid like that. But don't understand why the vent cannot be horizontal with a slop. If we can, remove red vent should be ok because the drain is 2" and the arm is 5'. So the stack end vent is also the vent of the first floor tub. I am not right?

    It seems I have to drill floor and break wall for the basement sink. too bad.
    Last edited by a moderator: Aug 5, 2013
  7. asktom

    asktom Member

    Messages:
    530
    Location:
    Victor, MT
    The tub vent shouldn't be horizonal with a slope because, well, that is the code. The thinking is that if the drain clogs up the water will back into the vent and it to can also become clogged. The drain can be opened and leave the vent stopped up. A clogged vent can cause subtle problems and be difficult to clear, depending on how the vent is run.

    The basement sink needs to be vented before it ties into the stack and the vent needs to tie into the tub vent 6" above the top of the tub. If the tub is clogged the water will run over the top of the tub onto the floor rather than taking an alternate route down the sink vent.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,515
    Location:
    Cave Creek, Arizona
    quote; The downstairs vent needs to tie in at least six inches above the top of the bathtub (assuming the tub is the only thing connected to that

    IT makes no difference whether a sink is connected or not, the code reads "42" above the FLOOR, or 6" above the overflow line of the fixture WHICHEVER IS HIGHER". The reason being that sometime in the future a sink COULD be connected to it and then it would be too low if it were just 6" above the tub.
  9. asktom

    asktom Member

    Messages:
    530
    Location:
    Victor, MT
    HJ is right.
  10. lmei007

    lmei007 Member

    Messages:
    161
    Location:
    Maryland
    These, option A and option B, are better or not. I understand "the 42" or 6" above rule" now.

    Are option A and option B the same?
    Are they valid?
    if yes, which one is better?

    Cannot understand this sentence: "IT makes no difference whether a sink is connected or not".

    Attached Files:

    Last edited by a moderator: Aug 5, 2013
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