Proper setup for double sink plumbing

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by samohtep, Mar 27, 2014.

  1. samohtep

    samohtep New Member

    Messages:
    3
    Location:
    Hamburg, NY
    Hi All,

    I thought this would just be a quick and easy job, but the more I look into it, the less I know how I should do this. I want to remove the garbage disposal from my kitchen sink. I posted a picture to another forum asking whether I needed p-traps on both drains. The current setup is a two bowl sink, garbage disposal on the left drain, and dishwasher hose connected to the disposal. There's a P-Trap from the disposal to the drain from the right bowl, then a goofy looped S-Trap where the outlet drops through the floor to the cleanout in the basement. The house is 90 years old and while the pipes aren't, they seem to have been pretty cobbled together over the years.

    Sink_Plumbing_1.jpg

    Sink_Plumbing_2.jpg

    The first response said 2 traps weren't needed, the second response but said I needed a vent.
    The second response confirmed 1 trap and vent, then explained the S-trap at the floor line.
    I called the town code enforcement office today and he advised me to check the New York State code.

    Also, I contacted a local plumber about the work, including a photo and here's the response:

    "It sounds like you r not having any problems with draining or venting
    **s-traps are ok to use and we still sell them. *If you are *remolding *them you might want to replum in pvc pipe with proper venting ."


    Sooo, yeah, I don't think I'll be trusting them to do it…

    Anyway, I saw this link:
    http://www.hammerzone.com/archives/kitchen/sink/drain/02/replace_old.htm

    The difficult bit that I keep coming back too is that the drop through the floor is only offset an inch or so from being directly beneath the right bowl. If it helps, I'll post a few better photos when I get home. Any suggestions would be greatly appreciated.

    Thanks
    Last edited by a moderator: Mar 27, 2014
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,487
    Location:
    Cave Creek, Arizona
    The disposer does NOT need that trap, but the "S" trap has to go. In order to reconnect the sink without the disposer, (NOT a "Disposal"), you need a continuous waste horizontal pipe, a flanged tailpiece out of the new sink drain fitting, and a dishwasher connection tailpiece between the strainer's tailpiece and the waste pipe.
  3. Terry

    Terry Administrator Staff Member

    Messages:
    14,889
    Location:
    Bothell, Washington
    I would like to see the disposer plumbed to a tee below the right sink. Also an AAV on the line coming up from the floor.
    If you need to offset on the vertical, that's fine.

    The dishwasher line should be strapped as high as you can in the cabinet before it enters the disposer, or install with an air-gap.

    The rest of the country quit doing S-traps decades ago. If I were New York, I wouldn't be bragging.

    And, it hurts my eyes looking at the handyman work on hammerzone.

    [​IMG]
  4. wjcandee

    wjcandee Wise One

    Messages:
    1,819
    Location:
    New York, NY
    Yeah, the NYC metro area doesn't seem to worry much about air gaps or high-loops on the dishwasher installs. In fact, when we had one installed recently, I suggested an air gap.

    "A what?"

    Great. They did know what a high loop was, but insisted it wasn't required. Swell. Do it anyway.

    I know for a fact, however, that an S-trap isn't going to be permitted.
  5. yngwie_69

    yngwie_69 New Member

    Messages:
    61
    Location:
    Prince Rupert, BC
    Cleanout

    If thats a galvanized tee cleanout, your doomed for constant plugging up.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,487
    Location:
    Cave Creek, Arizona
    he indicated that he was removing the disposer. That is a cast iron "drainage" tee, which was the required fitting when it was installed.
  7. SHR

    SHR Member

    Messages:
    96
    Location:
    Minnesota
    Thank you Terry for mentioning the Hammerzone link. Of course now I had to check it out. I share your horror! I can never "unsee" that incredibly bad work being passed off as the right way plumb. "Hammerzone" makes me want to hammer my head trying to get the images out of my mind! Even worse is the comments on the page are generally positive and thankful for the "good advise." It is a shame anyone with internet access can post really bad information as fact and mislead thousands of poor souls who just want help. Now back to the current thread...
    Last edited: Mar 28, 2014
  8. samohtep

    samohtep New Member

    Messages:
    3
    Location:
    Hamburg, NY
    Thanks all, I had seen the link for the Hammerzone page in a thread here, so thanks for the correction.
    Based on the comments, I put this together. (Grey existing, Red new)

    Plumbing_Diagram.jpg

    Is it completely insane? As I mentioned, the drop through the floor, is almost directly below the right basin, maybe an inch closer the the face of the cabinet and an inch to the right. Any corrections?
  9. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,244
    Location:
    Land of Cheese
    That would be a proper installation.
  10. Terry

    Terry Administrator Staff Member

    Messages:
    14,889
    Location:
    Bothell, Washington
    I like it too.
    and the drawing is amazing. :)
  11. samohtep

    samohtep New Member

    Messages:
    3
    Location:
    Hamburg, NY
    Awesome, thanks for the help.
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