How to connect PVC tub drain to ABS waste

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CheetahGeek

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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!
 

CheetahGeek

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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.
 

Terry

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mission_bandseal.jpg


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.

wood_4604.jpg
 
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CheetahGeek

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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.
 

Terry

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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.
 
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