Mixing PVC pipe with ABS pipe... Bad Idea Jeans?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by debo, May 28, 2008.

  1. debo

    debo New Member

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    Mixing PVC pipe with ABS pipe... Bad Idea Jeans? (pics added)

    I'm remodeling a bathroom and mistakenly did my drainage using pvc pipe. My house had ABS, and we used some of the ABS that we cut out together with the PVC. This was all glued together with PVC primer and cement.

    I didn't realize that the black pipe was not pvc until tonight when I was looking into drains. The pipes aren't leaking, but I've read you shouldn't mix the two, especially not with pvc cement. So, should I rip out the new drainage and put in all ABS? Or will it be ok to leave as is?
    Last edited: Jun 1, 2008
  2. rombo

    rombo New Member

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    Ontario
    rip it out and use transition cement
  3. Gary Swart

    Gary Swart In the Trades

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    Yakima WA
    Here's the problem. PVC and ABS are made for different chemicals. The so-called glue for them are also chemically different. Actually, they are not glues at all. They are solvents that briefly dissolve the surfaces of the pipes and fittings. After the piece are pushed together, the surfaces blend together and solidify. This forms a chemical weld. The problem is, since PVC and ABS are different materials, the solvent for one does not work on the other. There is a transition solvent that is supposed to work both ways. I haven't any personal experience with it. Another way to connect ABS and PVC is with no-hub banded couplers.
  4. go to lowes

    their is really no problem here...leave it alone....

    it probably wont come apart or leak anyway.........

    and the water does not care what kind of pipe it travels through.....


    all you got to do is get one of those types of glue that
    is supposed to be for all purpose....at Lowes....

    the last time I bought some it came in orange color.....



    If you feel that you must do it over

    just get a pvc or abs coupling and glue them together

    just throw it on extra thick on both the male and female ends

    it is no big deal...
    Last edited: May 29, 2008
  5. debo

    debo New Member

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    Probably?? That doesn't sound good....

    The problem is that I didn't use the all purpose glue, I used the pvc glue. I called up Oatey, they said it wasn't a good idea...
  6. jimbo

    jimbo Plumber

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    I have "played around" with this issue. What you will find is that you can take the joint apart with moderate hand force applied. The cement just doesn't penetrate the wrong plastic. SO, while the joint appears sound, and holds water now, over time normal vibration, house movement, set, the is a good chance that joint will crack and leak. I would not leave it.
  7. Redwood

    Redwood Master Plumber

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    7,450
    Location:
    Connecticut
    Mark... I see a problem... All Purpose is okay for putting either together... But, not mixing them.

    If you are combining materials either use a PVC/ABS Transition Cement or, use a banded coupling such as a Fernco Proflex.
  8. hj

    hj Moderator & Master Plumber Staff Member

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    pipe

    You may or may not have a problem but there is no way to tell until it happens. The ideal thing would be to take it all out and use the original ABS material for the connections.
  9. rombo

    rombo New Member

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    62
    Location:
    Ontario
    transition cement is good for abs/abs, pvc/pvc, and pvc/abs
  10. GrumpyPlumber

    GrumpyPlumber Licensed Grump

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    Licensed Grump
    Completely took the words outta my mouth.
    Had a debate with someone on the topic of transition solvents, apparently they make an approved solvent my state recently accepted.
    I wouldn't trust it...you said it all, especially not for the minimum cost and labor of a no-hub.
  11. debo

    debo New Member

    Messages:
    8
    I can't pull these the pvc pipes and the abs pipes apart. I guess I could saw them apart. I put some together with the solvent I used to see if I could get them apart. I beat them against some cement blocks and still couldn't separate them. But given the bond that seems to be there, are you sure I need to?
  12. Gary Swart

    Gary Swart In the Trades

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    Yakima WA
    It's your house, your risk. If it holds forever, then you save a few bucks. If it doesn't hold and you have to tear up you bathroom, repair all of the damage caused be a leak, you gambled and lost. If it was mine, I pull it all out, and go with ABS all the way and be sure.
  13. debo

    debo New Member

    Messages:
    8
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