Double vanity rough in

Discussion in 'Plumbing Code Questions' started by Alexpeter357, Nov 5, 2020.

  1. Alexpeter357

    Alexpeter357 New Member

    Joined:
    Nov 5, 2020
    Location:
    Michigan
    Hello everyone,
    I wanted to get some advice on a rough in I just did for a double vanity sink. This is my first time and so just wanted to get some advice and input of all you guys. I love the knowledge and experience on this page. Thanks in advance

    1442F186-282F-4B5F-A795-E66BBDAE245A.jpeg
     
  2. Sylvan

    Sylvan Still learning

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    Sep 23, 2004
    Occupation:
    plumbing - fire suppression - boiler inspector
    Location:
    New York
    Looks good
     
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  4. Terry

    Terry Administrator Staff Member

    Joined:
    Aug 17, 2004
    Occupation:
    Plumber
    Location:
    Bothell, Washington
    You should have 2" pipe when roughing for two lavs. Each trap arm can be 1.5"
    The vent can also be 1.5"

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    Last edited: Nov 5, 2020
  5. Alexpeter357

    Alexpeter357 New Member

    Joined:
    Nov 5, 2020
    Location:
    Michigan
    Thanks for the input Terry! I’m really kicking myself now because I glued everything. Rookie mistake. I’ve gotten mixed opinions, but really trust yours. I’ll have to make some cuts and rework it.
     
  6. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    2" is probably better, but IPC Table 710.1(2) allows 3 DFUs on a 1-1/2" horizontal branch. [Each lav is 1 DFU.] And Michigan appears to be on the IPC.

    https://up.codes/viewer/michigan/mi-plumbing-code-2015/chapter/7/sanitary-drainage#table_710.1

    Cheers, Wayne

    P.S. UPC Table 703.2 allows only 1 DFU on horizontal 1-1/2" pipe, 2 DFUs on vertical, so quite the difference.

    https://up.codes/viewer/california/ca-plumbing-code-2019/chapter/7/sanitary-drainage#table_703.2
     
  7. Alexpeter357

    Alexpeter357 New Member

    Joined:
    Nov 5, 2020
    Location:
    Michigan
    Thanks Wayne, just so I understand completely. As I have it technically “meets code” however best practice would be to have a 2” drain coming down
     
  8. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    You could improve that by putting a cleanout above your double santee. That would make for easy rodding down that 1.5 inch if it ever came up.

    Depending on how flush with the wall you want, you could use a santee with a cleanout cap. You could use a cleanout fixture, which sticks out less, and there are other choices that stick out under the vanity more.
     
  9. wwhitney

    wwhitney Well-Known Member

    Joined:
    Mar 17, 2019
    Location:
    Berkeley, CA
    I don't have the experience to say whether the performance improvement from upsizing the common drain to 2" would be worth the rework. I think adding a cleanout would be a good idea, and that would be simpler rework.

    I trust you're going to repair the stud with the missing segment? Particularly as that stud appears to support your tub surround on the reverse side.

    Cheers, Wayne
     
  10. Alexpeter357

    Alexpeter357 New Member

    Joined:
    Nov 5, 2020
    Location:
    Michigan
    Ok thanks for the input! I’m not sure yet what I’m going to do! I’m not psyched about reworking the drain to 2” but seems like from what I’ve read it may be the way to go.
    Oh yes, I fixed that. Builders ran hvac duct through there for a wall register ‍♂️
     
  11. Alexpeter357

    Alexpeter357 New Member

    Joined:
    Nov 5, 2020
    Location:
    Michigan
    Awesome! Thanks for the input! Makes total sense
     
  12. Reach4

    Reach4 Well-Known Member

    Joined:
    Sep 25, 2013
    Location:
    IL
    I would not. Adding a cleanout, which you might never need, is much easier.
     
    Alexpeter357 likes this.
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