Kitchen Island rough-in

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by jkhome, Dec 17, 2010.

  1. jkhome

    jkhome New Member

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    Hey folks, I have a couple of questions on how to rough-in a kitchen island. As you can see in the photo above, I have already roughed in a wall sink. We want to now relocate this sink to the island (thus the trench).

    I would like to leave the stack and cleanout at the present location (just get rid of the drain stub out). I will also add an AAV at the sink location, if I have to. The distance between vent and proposed sink is about 8'. Since the top of existing drain is about 9-1/2" from the top of the concrete slab, don't think I have the depth for a loop vent setup.

    The 2" drain line angle looks as if it will need 135 ? degrees of turns. So is it best to install a combo tee, or a wye tee, plus (what degree) other els to get to the direction of the island, code wise.

    As far the water supply, if using type L soft copper, what is the industry standard as far as sleeving? Or should I go with something other than copper? The lines on the wall side will be brought up in front of the finish wall, hidden inside a pantry cabinet, with cut-off valves.

    Thanks for any help
    John K.
    Last edited by a moderator: Jan 26, 2012
  2. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    It may be tight but I think you can get a proper foot vent in there, a lot of areas will not all the use of an AAV on a island sink. I left you a picture of the proper way to install a island vent.
    [​IMG]
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    I would do it by modifying the "standard" loop vent installation, but trying to describe it so you would do it correctly without screwing something up might be too difficult, and I do not want to go to the trouble of trying to insert a drawing. Suffice it to say, that there IS a way to get the foot vent installed, even though you do not have a lot of "headroom".
  4. jkhome

    jkhome New Member

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    Well you could give me a hint :^), but nevertheless, my local inspector has cleared me using a Studor. Believe you/me, I would rather do the loop. Knowing my luck, the AAV will fail on Thankgiving day, right when the bird comes out of the oven.

    But if the drain starts out at 9-1/2" below the top of the 4" slab, at an 8' run I'm up to 7-1/2". I just measured a combo plus vent tee, which places the top of the vent line starting at 9" above the drain, before it even slopes up towards the vent. The pipe would be outa the concrete, above the floor.

    Can't see how it will work, unless of course you want to let me in on your secret tip.

    Maybe I wasn't clear. All I need to know is if it's ok to use a combo plus a 45 degree elbow (both horizontally) to get the drain to the island, or would it be better to use a Wye tee plus multiple 1/8 turn els, to get that 135 degree turn. I would guess the latter.

    And the water sleeve material needed, foam insulation OK or should I go with some sort of oversized plastic tubing to run the copper inside. Thanks
    Last edited by a moderator: Dec 18, 2010
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    The "first" Y for the vent would be moved downstream, then rolled above the plane of the drain line, and a second one butted "face to face" against it.
  6. jkhome

    jkhome New Member

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    23
    Thanks HJ. I"ll pick up the fittings and post a pic of a dry fit, to show if I'm on the right track.
  7. jkhome

    jkhome New Member

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    How about that? Drain on the front el, tied up top to vent/loop on the back el (the spacing between the two els will be wider on the finished job). Should I go 2" on the vent pipe all the way to the cleanout on the wall, or can I reduce down to 1-1/2 at the wye outlet, and change everything downstream (on the vent pipe) to 1-1/2?
    Last edited by a moderator: Jan 26, 2012
  8. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    Run 2in. at least to the c.o.
  9. jkhome

    jkhome New Member

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    23
    Thank Shacko. So the foot vent I threw together looks good?
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    It does. Make sure you slope everything to the vent's Y. You also might want to move the y's downstream a ways to give yourself room to offset the risers closer together.
  11. jkhome

    jkhome New Member

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    Excellent, thanks for the help. This should work for me.
  12. jkhome

    jkhome New Member

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    23
    One last newbie question. Even though, using the above loop setup, one normally wouldn’t tie the vent and drain line together back at the wall, should I do this anyway to incorporate the wall cleanout, because of the fact that I will still have 135 degrees of turns going into the drain?

    So instead of going from the foot vent to a 45 plus a 90 into the existing drain, I should still do a 45 plus a combo, to go to drain and wall vent el?
    Last edited by a moderator: Dec 19, 2010
  13. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    quote; So instead of going from the foot vent to a 45 plus a 90 into the existing drain, I should still do a 45 plus a combo, to go to drain and wall vent el?

    You lost me there, since I have absolutely no idea what you are asking. The 135 degrees limitation is for the drain from the trap to the vent, not the vent itself. Do not make any other connections between the drain and the vent than what you have there.
    Last edited: Dec 19, 2010
  14. jkhome

    jkhome New Member

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    23
    LOL, you aren't the only one lost. Thanks, I'll pipe it like I'm supposed to.
  15. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,626
    Location:
    Cave Creek, Arizona
    Now maybe you see why I did not even want to try to tell you how to do it.
  16. jkhome

    jkhome New Member

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    23
    Have a Happy Holiday :^)
  17. jkhome

    jkhome New Member

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    23
    [​IMG]
    It fit, with a good 2-1/2" to spare from the top of the vent (highest point horizontally) to the top of the floor. Look kosher?
    Last edited by a moderator: Dec 22, 2010
  18. Basement_Lurker

    Basement_Lurker One who lurks

    Messages:
    668
    Location:
    Victoria, BC
    nice job. everything looks pretty good so far and i like the fact that you used a continuous run of soft copper for the supplies since you opted to use copper.
  19. jkhome

    jkhome New Member

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    23
    Thanks. I plan on adding some temporary wooden bracing to strap the pipes secure on the island end, wanted to get in a photo first.
  20. jkhome

    jkhome New Member

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    23
    Last comment on this thread. I had the rough-in inspection today, and the modified foot vent (along with everything else) passed with flying colors. The inspector did mention a "one pipe solution", I voiced my concern with AAVs, and he agreed.

    So a final thanks to all who helped, have a happy New Years!
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