I might have messed up big-time with drain pipe rough-in location

Discussion in 'Remodel Forum & Blog' started by Tim222, Apr 13, 2014.

  1. Tim222

    Tim222 New Member

    Messages:
    24
    I am a DIYer. The drain connects to the main vent 24" o.c. from the floor:

    roof
    ||
    ||
    ||
    ||
    ||...............\__sink__/
    ||=====O
    ||
    ||
    ||
    ||
    ________________________________


    A different deeper sink was chosen. The bottom of this sink is 25" from the floor. The standard wall piece and P-trap don't fit. See pic.

    Is it permissible to extend the piece coming out of the wall vertically by about 3", to lower the P-trap? Is there by code a maximum distance between the bottom of the p-trap and the point where the drain pipe enters the wall?

    Drain.jpg
    Last edited by a moderator: Apr 13, 2014
  2. Smooky

    Smooky Member

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    626
    Location:
    NC
    Last edited: Apr 13, 2014
  3. cacher_chick

    cacher_chick Test, Don't Guess!

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    It looks to me like the inlet in the wall is about the same height as the bottom of the sink. The sanitary tee in the wall needs to be lowered on the stack. A deep sink needs the tee inlet 16-18" above the floor.
    Last edited: Apr 13, 2014
  4. Tim222

    Tim222 New Member

    Messages:
    24
    The angle of the photo makes them look the same height. The sink bottom is 1" above the drain.
  5. Tim222

    Tim222 New Member

    Messages:
    24
    Thanks for the links, Smooky.

    There is a popup assembly in the tailpiece. I take it there is simply no way to use 90-degree PVC elbow and drop a vertical pipe from it to the correct length, possibly together with the J-Bend-Lo-Inlet?
  6. Smooky

    Smooky Member

    Messages:
    626
    Location:
    NC
    My thought is with a different tail piece and drain type of course it might work with the j-bend you have or the lo-bend p-trap as it is supposed to work. The deeper you go with the p-trap the slower it will drain and the sooner it will clog. You could try it and see. No big expense to try but in the long run I think you will have problems. Also everything below the outlet level will be full of water all the time, so it could leak more easily with more joints below the water line.
  7. cacher_chick

    cacher_chick Test, Don't Guess!

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    If you make the trap deeper, it will not be self-scouring and will not drain properly. Your choices are to lower the fitting in the wall or raise the vanity so the sink is higher.
  8. Tim222

    Tim222 New Member

    Messages:
    24
    Believe me, I believe you. But lowering the fitting in the wall is not possible -- there are just too many obstructions inside the wall. Raising the vanity sink by only 5" is not possible. I'd have to raise it by more than that (about 9") by totally replacing the undermount sink (already installed) with a vessel sink, and then I'd have to figure out a way to modify the granite countertop with its 19x13 cutout to support a vessel sink.

    What about something like the attached picture from a plumbing supply catalog? With its long vertical piece, it looks as though it's designed for my scenario, where the wall inlet is not far enough below the sink drain. Is it possible to try it and see how it works, or is this a clear code violation?

    PTrapLongVertical.png
    Last edited by a moderator: Apr 14, 2014
  9. cacher_chick

    cacher_chick Test, Don't Guess!

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    Location:
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    The sink would not drain properly.

    On many vanities, you could increase the height of the toe kick and trim it out so that it looks fairly normal.

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