P-trap Arm Vertical Drop

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Allison, Feb 17, 2020.

  1. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    Would the below set up pass UPC as long as the trap weir is less than 1.25" above the connection on the double fixture fitting? I only see 1002.4 requiring that the trap weir be above the vent pipe opening. All pipes and fittings are 2".
    upload_2020-2-17_10-57-8.png

    Background: I am currently working on plumbing back to back bathrooms with majority of drains running in the basement. I've run into an issue where one shower P-trap will end up lower than the joists based on the height the double fixture fitting has to be at in order for the other (further away) shower P-trap arm to be at a 1/4"/foot slope. The current slope is too steep from the second P-trap to the double fixture fitting if the P-trap is within the joists.

    Thank you!
    Allison
     
  2. James Henry

    James Henry In the Trades

    Joined:
    Jul 23, 2019
    Occupation:
    Plumber
    Location:
    Billings, Montana.
    Try stacking 2 santee's on top of each other. If it works, that's legal.
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. James Henry

    James Henry In the Trades

    Joined:
    Jul 23, 2019
    Occupation:
    Plumber
    Location:
    Billings, Montana.
    They make a street santee.
     
  5. plumber01

    plumber01 In the Trades

    Joined:
    May 13, 2015
    I think you're mixed up.

    1002.4
    The vent pipe opening from a soil or waste pipe, except for water closest, shall NOT be below the weir of the trap.
     
  6. James Henry

    James Henry In the Trades

    Joined:
    Jul 23, 2019
    Occupation:
    Plumber
    Location:
    Billings, Montana.
    You could be right. I just know that fixture drains on a common vent can be stacked as long as the top fitting is sized as a vertical wet vent. Not sure if it's the solution for his situation.
     
    Last edited: Feb 18, 2020
  7. plumber01

    plumber01 In the Trades

    Joined:
    May 13, 2015
    Agreed. My post was directed at Allison.
     
  8. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    Oh you are right sorry I mis-quoted the code, assuming that the vent pipe is opening is above the trap weir would this set up pass UPC? I don't think I can get stacked san-tees to work without running into a similar issue.
     
  9. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    I've realized through this question that I think my current set up has the trap weir above the vent opening due to the double fixture fitting, I am going to use to separate san-tees tying in to the horizontal line with separate wye+45s which will solve both of these issues. Thank you for your replies!
     
  10. James Henry

    James Henry In the Trades

    Joined:
    Jul 23, 2019
    Occupation:
    Plumber
    Location:
    Billings, Montana.
    Your current setup is a semi s-trap and that is illegal. Do not use a wye+1/8 bend on a vertical drain, that is also illegal. Use santee's.
     
    Last edited: Feb 18, 2020
  11. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    Just for clarification is it ok to use wye+1/8(double fixture fitting) vertically for back to back toilets? And back to back sinks? I see this image on here a lot for double sinks. [​IMG]Thank you again!
     
  12. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    Not sure if this helps, but here is where I am currently at: setup2.PNG
     
  13. James Henry

    James Henry In the Trades

    Joined:
    Jul 23, 2019
    Occupation:
    Plumber
    Location:
    Billings, Montana.
    Yes. A double fixture fitting is meant to be installed vertically for back to back lavs not toilets. But a wye and 1/8 bend going from horizontal to vertical for a lav is illegal.
     
  14. Allison

    Allison New Member

    Joined:
    Dec 5, 2019
    Location:
    Portland, Oregon
    ok thank you!
     
Similar Threads: P-trap Vertical
Forum Title Date
Plumbing Forum, Professional & DIY Advice Max vertical distance out of p-trap before going into trap arm Mar 31, 2012
Plumbing Forum, Professional & DIY Advice vertical distance to p-trap for washing machine Jul 3, 2011
Plumbing Forum, Professional & DIY Advice No reason for sealant on PP kitchen p-trap, right? Mar 29, 2020
Plumbing Forum, Professional & DIY Advice Replacing Bathtub S-Trap with P-Trap Mar 27, 2020
Plumbing Forum, Professional & DIY Advice Can I turn the outflow side of a p-trap? Mar 25, 2020

Share This Page