"undoing" joint in abs plumbing stack?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by tgunn, Sep 9, 2004.

  1. tgunn

    tgunn New Member

    Messages:
    5
    Hello,
    I've got a "unique" problem to try to solve. The previous owners of my house spliced into one of the plumbing stacks for the washing machine as shown in this picture:
    [​IMG]
    I'd like to keep the existing pipe for the washing machine drain, but I'd also like to put in a sink down the wall from this about 16-20 feet. Since the p-trap is right at the stack, it would seem I need to eliminate the p-trap at the stack and then put a trap at the washing machine drop, and then again at the sink I'd like to install.

    As you can see from the picture all of the joints are tight together with NO gap at all. There's about a 1/4" pipe showing at the T off the stack, but other than that everything is tightly fit, right to the floor. Starting again above the expansion joint is too high off the ground for the sink drain.

    Anyone have any ideas how I could some how undo one of the abs joints so I can replumb things? Or what other options am I missing? I don't think it's okay to have a trap at the stack and then a trap on the sink later on, is it?

    Thanks,
    Tyler
  2. greglowe

    greglowe DIY Junior Member

    Messages:
    4
    I know they make special drill bits for drilling out the pipe from a joint. perhaps you could cut at the bottom of the tee, then drill out the remains of the pipe. I have never used one of these bits, but I have seen them.
  3. tgunn

    tgunn New Member

    Messages:
    5
    Hmm, interesting, I found a drill bit that looks like it would do the trick.

    I'll have to see if I can find one of those at the store. They seem a bit pricey, so I guess for this one-off job I could cut off as you mentioned and use my dremel with a sanding drum to carefully clean the old pipe out of the fitting.

    Thanks for the idea! I think this might just work.

    Later,
    Tyler
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    drain

    The thing that is missing on the current installation, and you do not mention either is a vent. The existing tee may have been installed into a drain for an upstairs fixture, unless this is a single story house. In which case it should have been vented separately, but the distance you are going does require a separate vent connection, and you, or someone, will have to determine whether it can be connected back to this same pipe or has to terminate somewhere else.
  5. tgunn

    tgunn New Member

    Messages:
    5
    This installation is in the basement of a single storey house. The pipe that goes upstairs is for the kitchen sink and dishwasher. It is vented directly to the roof.

    I was planning on putting in a vent for the new fixture and running it back along the floor joists in the basement to the stack shown in the picture (since it's vented itself, this should be okay as far as I'm aware).

    Thanks for the input!
    Tyler
  6. tgunn

    tgunn New Member

    Messages:
    5
    Correction, I looked in my local plumbing code and since that pipe services fixtures upstairs before it's vented, I'd have to connect the vent for the new basement sink ABOVE where the fixtures are connected upstairs....

    Hrm, there is a roughed in sink fixture on the other side of the basement; I guess I could always tie into the vent for that sink (it's right beside the main stack; the vent from that sink goes up to the main floor, and I'm assuming it joints back to the main vent later up in the wall somewhere.

    It's a long run (about 25-35 feet) from the sink I'm adding to that vent, but it's the only other one.

    Thanks,
    Tyler
  7. Deb

    Deb Plumber

    Messages:
    200
    Location:
    Idaho
    Deb

    I have personally had the best luck with the following method for removing old ABS pipe from a hub that I need to reuse.
    I cut the pipe right at the hub of the fitting. I make small slices through the pipe with a saw or dremel tool about 1" apart. I make a depth mark on my cutting device so that I do not accidently cut through the fitting. I heat the pipe up slightly with a heat gun and very carefully use a 1" chisel to chisel out the piece of pipe. The first ones are the hardest. It should still take under an hour--you appear to have good access where you are working (I usually have my head in a hole in the floor when I am trying to do this ;-)
    I have never had much luck with the drill bits meant for this purpose.
    Make sure that you get the venting correct, know your trap arm maximums, Know the standpipe and trap rules for a washer, and use the right fittings (san tee and wyes w 1/8th bends each have their own purposes are are not interchangeable) in the right places.
    Deb
    The Pipewench
  8. e-plumber

    e-plumber DIY Senior Member

    Messages:
    137
    Location:
    New York
    Do it all over

    Another idea would be to cut it all out and start over.
    Cut the ABS level with the floor and chisel around the pipe just enough to install a coupling, rearrange the drain piping as you need to and install proper vents
  9. tgunn

    tgunn New Member

    Messages:
    5
    I think my approach will be to uncouple everything above the cleanout and then start fresh from that point. I'm definitely leaving the pipe alone once it goes up to the next floor since I don't fancy the idea of ripping up the cupboards and walls to re-do everything in there. :)

    Thanks for the tips!
  10. srdenny

    srdenny Plumbing Contractor

    Messages:
    361
    Location:
    SF Peninsula
    undoing the joint

    I vote for e-plumber's suggestion. However, our original correspondent is clueless as to how to proceed. I think it's time to hire a professional.
    SR Denny
  11. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Messages:
    319
    Location:
    Wichita, Kansas
    Reads Books

    tgunn read a plumbing code and understood that his original venting idea won't work. I won't consider him clueless. Good of hj to spot his original vent problem.
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