does double kitchen sink require two traps?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by marktd, Aug 17, 2014.

  1. marktd

    marktd New Member

    Messages:
    3
    or can both go through one? Anything not kosher about that shown in attached pic?

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  2. Smooky

    Smooky Member

    Messages:
    626
    Location:
    NC
    One trap is fine. The trap arm should not dip down the way you have it, but it might work.
  3. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,265
    Location:
    Maine
    It doesn't but sometimes it's easier to do it that way. I don't like what you have there because the disposer is going to and water flying towards the sink basket.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,032
    Location:
    Cave Creek, Arizona
    They have the wrong fitting where the two drains join and the trap arm has a partial "S" tarp. Someone got very creative and spent a lot of time making that mess.
    SHR likes this.
  5. marktd

    marktd New Member

    Messages:
    3
    I think the reason for the bend in the trap arm is that if it were horizontal, the drawer would hit the trap. Is there some concern about that bend? I could get rid of the dip by notching the drawer.
  6. Reach4

    Reach4 Well-Known Member

    Messages:
    2,634
    Location:
    IL
    Yes. An alternative to notching the back of the drawer would be to locate the trap to the right over the lower and backless drawer.
  7. marktd

    marktd New Member

    Messages:
    3
    Actually, the right side has same drawer. It's just not visible because the drawer is pulled out to allow picture to be taken.

    I think a more conventional layout with slip joint fittings might fit without drawer trap interference. For example, the disposer rotated so outlet points toward other sink, sink drop tube, tee, etc. But that would interfere with the waste basket arrangement in the right drawer (not visible in picture). The current setup was an attempt to push the drain close to the wall to maximize space.

    It works now, but as Tom Sawyer above guessed, the disposer pushes water into the other sink basket. So I am looking to fix that, but try to preserve the waste baskets.
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,032
    Location:
    Cave Creek, Arizona
    "convenience" is never a reason to do it incorrectly. We would have to see the actual installation, with the drawers in place to determine the better way to do it.
  9. asktom

    asktom Member

    Messages:
    587
    Location:
    Victor, MT
    Just curious, are plumbers working under the UPC putting two traps on one trap arm and getting away with it? Unless it has changed in the last few years, 1001.1 states, "Not more than one (1) trap shall be permitted on a trap arm." We got called on it in the Los Angeles area, back in the day - but it sounds like it may be a common practice other places. The law is as the law is inforced, is this a case where inspectors put fingers in their ears and hum? Has the code change since 2000?
  10. SHR

    SHR Member

    Messages:
    127
    Location:
    Minnesota
    You have an S-trap. S-traps are dangerous. Correct the plumbing.
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