How to connect PVC tub drain to ABS waste

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by CheetahGeek, Dec 19, 2013.

  1. CheetahGeek

    CheetahGeek Engineer

    Messages:
    4
    Location:
    Seattle
    I'm trying to figure out how to install a p-trap for an acrylic freestanding bathtub. The tub has an integral overflow. I'm working in the basement. A plumber started the work but moved off to a higher priority job just after the rough in (sans the p-trap) was approved and before the slab poured. I put a 12x12 box around the ABS waste pipe centered at the tub drain location so there is an opening in the concrete. Unfortunately this guy is a great plumber but not a great communicator. He told me that he was planning to install the p-trap with a riser that would be glued to the tub drain. There would be one shot at 'dropping' in the tub.

    I know venting is going to be one of the first things you're going to ask about so I can tell you that it is connected properly for the tub, and has been signed off by the inspector along with the rest of the rough in. :D

    Where I'm stuck is that the tub drain is PVC and the waste pipe is ABS. I know how to install a p-trap and I have the space but I can't glue PVC and ABS. I'm assuming I'll need a banded coupler but where do I put it? Between the PVC drain stem and an ABS riser? Seems like that's asking for a leak. Does the coupler go between the ABS horizontal with a PVC p-trap and glue down the drain? Still seems like a leak risk.

    I'm also wondering if there is another way of installing the p-trap and tub that gives more than one shot at getting the install right.

    Help!
  2. CheetahGeek

    CheetahGeek Engineer

    Messages:
    4
    Location:
    Seattle
    After looking at another thread I may have answered at least one of my questions. Let me know if I've got this right.

    Install ABS p-trap. Use a p-trap adapter with slip nut. Slip nut on PVC drain side, connect first, then glue adapter (ABS side) to ABS riser already glued and perfectly sized. Still a one chance install. Not sure how to test or remove.
  3. Terry

    Terry Administrator Staff Member

    Messages:
    15,011
    Location:
    Bothell, Washington
    [​IMG]

    Plastic to plastic coupling like this for going from ABS to PVC if you have shedule 40.
    If you have a tubular size waste and overflow, then it would be a trap adapter using a slip joint nut.
    It depends on your waste and overflow. The Kohler tubs I've installed have the glue together waste and overflow and use the coupling above.

    [​IMG]
    Last edited: Dec 19, 2013
  4. dj2

    dj2 Member

    Messages:
    415
    Location:
    California
    Why can't you get an ABS bath waste set?
  5. CheetahGeek

    CheetahGeek Engineer

    Messages:
    4
    Location:
    Seattle
    Terry - I'm not sure where to put the coupler that you show in the picture in our post.
    dj2 - the tub drain is integrated and can not be replaced. I'm assuming that's what you mean by waste set.

    If I need the coupler I'm not sure where to connect it.
  6. CheetahGeek

    CheetahGeek Engineer

    Messages:
    4
    Location:
    Seattle
    Can the coupler be embedded in concrete?
  7. Terry

    Terry Administrator Staff Member

    Messages:
    15,011
    Location:
    Bothell, Washington
    The coupling can be in concrete, though normally you have space under that connection unless you intend to pour concrete in afterwards. I don't know who does that though.
    We may need some pictures of the parts you're trying to install.
Similar Threads: connect drain
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & 3" drain connection questions Aug 4, 2014
Plumbing Forum, Professional & DIY Advice, Tips & help with shower drain connection Aug 1, 2014
Plumbing Forum, Professional & DIY Advice, Tips & connecting two horizontal drain line with wye fitting Jun 5, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Shower drain: How best to connect PVC to ABS? Mar 30, 2014
Plumbing Forum, Professional & DIY Advice, Tips & How to Connect Sink, Dishwasher and Laundry Pump to One Drain Pipe? Mar 5, 2014

Share This Page