How to vent first floor toilet? Which waste line run is best?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Rob2, Jun 24, 2014.

  1. Rob2

    Rob2 New Member

    Messages:
    6
    Location:
    KY
    First question.
    Can I install a vent in the form of 4x2x4 Sani Tee or Wye rolled above centerline on the horizontal portion below the first floor directly behind the 4x4x4 Combo Tee Wye with the first floor toilet feeding into this Combo, or does the vent have to be installed directly in front of this Combo Tee Wye fitting in order to correctly locate the vent for the toilet? Essentially which point; point A or Point B in the attached diagrams?

    Both would be after the trap of the toilet, but if it is installed behind this Combo fitting, it would result in a 4-6 inch wet vent. If installed behind this Combo, the vent line could continue from the Wye at the required 45 degrees for vent line until getting to the vertical chaseway, but if installed in front of this Combo, the vent line would only be about an estimated 20 degrees at best until getting to the vertical chaseway, where 2 inch vent runs vertical.

    Second question.
    Which Run number (either Run 1 in black, Run 2, or Run 3 both in red) is both legal and would drain the best? Run 2 is only 35-40 degrees from vertical so it is still considered a vertical run. My thoughts are that Run 1 would drain the worst, Run 3 better than run 1, and Run 2 the best.

    If there is anything else that I missed with this diagram please let me know. Thanks in advance for all help and constructive advice!!! I mistakenly posted this in the wrong forum heading.

    Plumbing Diagram 2014 (3).jpg

    Plumbing Diagram 2014 (1).jpg
    Last edited by a moderator: Jun 24, 2014
  2. Reach4

    Reach4 Active Member

    Messages:
    1,933
    Location:
    IL
    Get rid of the trap for the toilet at point A. The toilet has the trap built into it.

    Of course I may be misinterpreting your drawing.
  3. Terry

    Terry Administrator Staff Member

    Messages:
    14,805
    Location:
    Bothell, Washington
    The drawing is confusing.

    When I'm stacking plumbing, it's more like this.

    [​IMG]
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,304
    Location:
    Cave Creek, Arizona
    Point "A" is where the vent should go. Point "B" is a "flat vent", not a "wet vent". As far as your toilet is concerned ALL the options are equal.
  5. Reach4

    Reach4 Active Member

    Messages:
    1,933
    Location:
    IL
    From what I have read, I don't think you require a long sweep ell on #2 horizontal to vertical at the top of run 1. It would be OK of course. You should use long sweep for horizontal to horizontal and vertical to horizontal, as on run 3.
  6. Rob2

    Rob2 New Member

    Messages:
    6
    Location:
    KY
    Attached is a simpler diagram.

    P6251232.jpg To diminish the crowded and busy previous diagrams, I have attached another diagram with view perpendicular to Point 3 to Point 4 which shows my first question a little better. In this diagram I have attached the first floor toilet vent at Point B which will allow me to continue vent of toilet at a 45 degree angle, but is there a wet vent of 4-6 inches from where the 4x2x4 Sani-T (or Wye) fitting butts up to the 4x4x4 Combo TY fitting? And would that little bit of wet vent be better than venting the toilet at Point A. At Point A the 2 inch vent coming out at this location would only be 15-20 degrees which would not be at the required 45 degrees, or can a toilet dry vent be flat vented for a short distance?
    Last edited: Jun 25, 2014
  7. Rob2

    Rob2 New Member

    Messages:
    6
    Location:
    KY
    So are you saying that I can not place the vent at POINT A. If so, what is the reason? When you said "As far as your toilet is concerned ALL options are equal" does your comment mean that they will all drain the solids equally well? If so, does it mean that I will not need a clean out on the 90 degree horizontal change of direction at Point 3 for Run 1? I think Run 2 and Run 3 would not need a clean out at Point 3. Would Run 2 (at 40degrees from vertical) drain the solids the best?
  8. Rob2

    Rob2 New Member

    Messages:
    6
    Location:
    KY
    You are correct, but a long sweep 90 would snake easier than a regular 90.
  9. Rob2

    Rob2 New Member

    Messages:
    6
    Location:
    KY
    There is no trap at point A.
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,304
    Location:
    Cave Creek, Arizona
    ALL options 1, 2, or 3 NEED a cleanout where the enter the floor where you indicate there is one. IF you need a cleanout at #4, then you have a very "lousy" installation and it has nothing to do with which option you chose. It means YOU did a very, very poor job of putting the piping together.
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