(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 8 of 8

Thread: Kitchen Sink Waste Outlet Height?

  1. #1

    Default Kitchen Sink Waste Outlet Height?

    In order to install a deeper kitchen sink with a disposer, I need to lower the waste outlet so that the disposer does not become the trap.

    Since this is 60 year old plumbing, I plan to use 2" PVC, run a new drain through the floor, into the basement, and tie into a cleanout in the original pipe. I will use the existing waste outlet as a vent (since it is vented and will be higher).

    My question: How many inches above the floor should I make the center of the waste outlet pipe? Is there any standard?

  2. #2
    Aspiring Old Fart, EE, computer & networking geek Mikey's Avatar
    Join Date
    Nov 2005
    Location
    Central Florida
    Posts
    2,686

    Default

    What really matters, obviously, is how far the disposer outlet will be above the floor or below the sink. Once you know that, you can set the drain at that level.

    Mine is 14 1/2" above the floor, and nicely accomodates a huge Insinkerator disposer and a deep sink (outlet is 11" below the countertop), with about a 5" fall from the disposer outlet to the trap.

    I don't know if this is legal, but if you're running a pipe straight down to the basement, put the trap down there as well, and cut the pipe to a suitable height and put in the fittings after the fixtures are installed.
    Last edited by Mikey; 08-05-2007 at 04:46 PM.

  3. #3
    Commercial Plumber markts30's Avatar
    Join Date
    Sep 2006
    Location
    Phoenix, AZ
    Posts
    630

    Default

    Quote Originally Posted by Mikey
    I don't know if this is legal, but if you're running a pipe straight down to the basement, put the trap down there as well, and cut the pipe to a suitable height and put in the fittings after the fixtures are installed.
    Here, tailpieces (vertical pipe connecting the sink drain to the trap) cannot be more than 24" long...
    Best best would be to open up the wall and lower the waste in the wall - not use a cleanout in the basement....

  4. #4
    In the Trades Gary Swart's Avatar
    Join Date
    Sep 2004
    Location
    Yakima WA
    Posts
    7,246

    Default

    Definitely agree with Markts30. Cutting out a section of drywall and patching it is a pretty simplistic job, especially since the patched area will be under the sink and never exposed to public view so even a less than professional job of patching will never be seen. The time to do this job right is now, don't let yourself try shortcuts that you will later regret.

  5. #5
    Licensed Grump GrumpyPlumber's Avatar
    Join Date
    Jun 2007
    Location
    Licensed Grump
    Posts
    1,404

    Default

    Mark & Gary...both 100% right.
    running the drain straight down to the basement sets up for an S-trap...they also tend to go over the 24" standpipe rule.
    What you do now stays with you for years to come...that could mean sewage smells in your kitchen.
    "The biggest regrets we have in life are the chances we never took."

  6. #6

    Default

    The current waste outlet is 22" above the floor. I guess this was what they used in 1949.

    The problem is that the current outlet is galvanized iron, and does not go down inside the wall, but makes a left turn for about 3 feet (running horizontally), till tying into (all 2" galvanized) a vertical pipe which runs from a vent upstairs and down to the basement. (I think they did it this way because the sink is above a basement window, but that has been now covered).

    What I want to do is use the current J trap, but have a PVC pipe with a sani-T, and have run down (near the wall) to the basement.

  7. #7
    Licensed Grump GrumpyPlumber's Avatar
    Join Date
    Jun 2007
    Location
    Licensed Grump
    Posts
    1,404

    Default

    If the galvy is openly exposed...take it out.
    Replace every inch you can.
    "The biggest regrets we have in life are the chances we never took."

  8. #8
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,651

    Default drain

    A trap under the floor does not automatically make it an "S" trap. You can use the opening in the wall for the vent, but not the way it is connected at this time. It will have to be modified first, but only someone there can tell what has to be done to make it a legal vent.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •