How to insert a WYE under slab???

I am adding a toilet and sink in my basement. I have a permit and have cut up the slab and have located the 3 inch ABS drain pipe. I know how the pipes will flow and I have a vent pipe located. Everything is ready but....

I am not sure how to insert the 3 inch Wye into the existing 3inch ABS drain pipe under the slab.

I know about a fernco fitting and bought one at Home Depot. It is a 3 inch plastic to plastic one that is all rubber with a clamp on each end. I think I read here those could not be used underground. Is that true?

My plan was to cut a section of the current 3 inch ABS out and leave room to attach a small stub pipe to one end of the WYE. Then slide the Fernco fitting over the other end of the existing pipe, insert in the WYE with the stub piece so there is about a 1/4 gap between the stub piece and the existing pipe and then slide the fernco over this 1/4 inch gap and tighten the clamps after I glue the WYE to the other existing piece.

Can this fernco fitting be used underground? Or do I need one of these with a metal sleeve? I keep seeing a picture od a PROFLEX fitting but can find none online.

Also, can someone tell me is a SLIP fitting would be better? It sounds better but seems like once I apply the glue you have to move really quickly to make it work.

Any help would be so appreciated.

Hi George,

"My plan was to cut a section of the current 3 inch ABS out and leave room to attach a small stub pipe to one end of the WYE. Then slide the Fernco fitting over the other end of the existing pipe, insert in the WYE with the stub piece so there is about a 1/4 gap between the stub piece and the existing pipe and then slide the fernco over this 1/4 inch gap and tighten the clamps after I glue the WYE to the other existing piece."

Sounds good to me with one exception. I would change from a Fernco Neoprene Coupling to a more ridged NO-Hub Band, Neoprene couplings are not ridged and will sag in time leaving a dip in the line that could cause a clog. Good luck, Tom

Thank you so much for your help.
What brand would I look for for the ridged NO-Hub Band? I didn't see any at home depot so I need to find a plumbing supply in kansas city. Do you know a company that makes them?

Why are you afraid of ABS cement? It'd be more permanent. If you're really squeamish, practice first to get a feel for dry fitting and how fast you have to work. There are fast-setting, medium-setting, and slow-setting types of cement. Get a can with a large diameter dauber so you can cover the pipe quickly. Cover the outside and the inside of the fitting. It's really not that bad...

Thanks for the post!!
I am not worried about it but just didn't know if I would have 15 seconds to work with it or 2 minutes before it would stop sliding. I like the slip joint solution better heard that it would start to bind before I could work with it.

If you want to go cement, just practice. You have about 15-25 seconds but that's a long time. Cement melts the plastic so the 2 pieces fuse together. It's a very strong, reliable bond.

A caveat: if you dry fit, then account for the fact that a 'dry' pipe won't slide in as far as a 'wet-with-cement' pipe will. A wet pipe will bottom out pretty easily

Geo said:

Thank you so much for your help.
What brand would I look for for the ridged NO-Hub Band? I didn't see any at home depot so I need to find a plumbing supply in kansas city. Do you know a company that makes them?

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No-Hub Bands can be found at any plumbing wholesale house. But if you have to order from online go to; http://www.idealclamp.com/ Prashster gave you good advice about gluing ABS fittings. ABS and PVC glue sets up pretty fast so when I prime and glue a fitting with a branch outlet I always put a small torpedo level on the branch and give it about a 1/8th of a bubble slope back to the main. Good luck, Tom

ABS does not use primer.

Gary Swart said:

ABS does not use primer.

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Thanks Gary,

My bad!! You're entirely correct. It's been so long since we used ABS in my area I forgot all you have to do is wipe the fitting clean. I'll go back and correct my post. Thanks for picking up on that. Regards, Tom

"Y"

Stick with the mechanical couplings. You, or anyone else, is not fast enough to install the "Y" using slip couplings, even if you could find them, (and if you did locate them they would be four times the price of a regular ABS coupling and at least twice the price of the mechanical couplings). No-hub couplings will work, although they are a bit too small and some inspectors will not pass them when used on ABS plastic. There are banded couplings labeled specifically for ABS and other sch. 40 pipes, and they are the ones that make inspectors happy.