Laundry Tub with No Visible Trap

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by sbaitso, Jun 3, 2006.

  1. sbaitso

    sbaitso New Member

    Messages:
    19
    In my basement is a laundry tub (aka stationary tub) that the washing machine drains into. For some odd reason, it has no trap. There is simply a straight length of PVC drain pipe that was somehow fitted into another larger pice of PVC that goes under the slab. The house was built in the '20s, so it is an older home. Is there a chance that there is a trap under the slab? I have never smelled any sewer gas, and it otherwise functions fine. Is this fairly standard? or would I need to install a trap?

    I'll try and post some pics to illustrate.


    Thanks for any advice. I'm really learning alot from this forum.
  2. brownizs

    brownizs In the Trades

    Messages:
    196
    Location:
    Springfield, IL
    It is possible, but you wouldn't know, unless started busting slab.
  3. sbaitso

    sbaitso New Member

    Messages:
    19
    some pics... if they provide any help. And after looking again, I don't think its PVC thats under the slab. Its so covered in stuff that its hard to tell.

    Attached Files:

    Last edited: Jun 3, 2006
  4. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    In the house where I grew up, they drained the laundry sink in the basement to a sump, and it pumped out into a separate drywell in the back yard. I presume this was to keep the laundry and ground water in the sump out of the septic.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    pipe

    They didn't even have PVC in the 20's. It is probably a clay tile pipe at the floor, but whether it has a trap or not can only be determined by being there and checking it.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,324
    Location:
    New England
    If you can see standing water in the bottom of the pipe, it probably has a trap.
  7. Ron Coleman

    Ron Coleman New Member

    Messages:
    8
    Location:
    Columbus, Ohio
    My guess is that the tub drains into an old floor drain and someone extended it with some pvc and cemented in the drain pipe. Probably to contain the frequent floods.

    The classic problem of water backing up when the washer pumps out is evident from the rusty legs on the tub frame. There is most likely a cast iron p-trap just under the surface.

    Ron
  8. sbaitso

    sbaitso New Member

    Messages:
    19
    I was wondering if it was something like that... though there is another floor drain about 6 or 7 feet from where this drain is. That drain is in a lowspot on the basement floor, while this one with the sink is not.

  9. go get a repair "s trap"

    if you are worried about it
    you should be able to go find an old style "S trap"

    and install it into that space you have to work with...



    Yes, I know that "s traps" are illegal for new construction

    but its fine for what you gotto work with
  10. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,736
    Location:
    Central Florida
    Alphabet soup

    Could you briefly explain the difference between S, J, P, etc., traps? Every trap I've ever seen looked pretty much like all the rest, but I never paid close attention.

    -mike
    (clearly, not an expert)
  11. prashster

    prashster New Member

    Messages:
    941
    Not sure what J Trap is. I thought it was just the 'wrong' name for a p trap.

    S trap has a vertical tail piece. S traps are 'illegal' anymore because they can cause trap siphoning. P trap has a longer horizontal tail piece that has a vent at or before the vertical transition.

    But yr right, they both look the same - between the fixture and the trap.
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    trap

    A "J" trap is really the "J" bend for a "P" trap. Do not put an "S" trap on your sink until you verify that there is not actually one below the concrete, or you will have a sink tht might not drain at all.
  13. sbaitso

    sbaitso New Member

    Messages:
    19
    I guess I'll just have to move the sink and peer down the drain to see if there is any standing water. Chances are I would have smelled something foul if there was no trap, correct?

    My hope is to someday move the sink over a foot or two so it sits in a location that is easier to get to... but I'll obviously have to keep the drain at the same spot in the floor.

    Thanks for all your input.
  14. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    If a floor drain was near by, then its probably an old cleanout. Undo the drain and take a look with a flashlight for water.

    Jason
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