Hi everyone, I'm from BC, Canada. I am at the rough in process for plumbing my basement in and decided to do it myself because the prices for a plumber here are ridiculous. I've been told that I could use abs for all the in ground plumbing but as soon as the plumbing leaves the concrete I need to switch to abs. My question being, do I need an adapter to go from 3" pvc to 3" abs? I ask this because the 2" pvc to 2" abs seemed to fit snuggly and I did not put an adapter on it. All the pvc I'm using is CSA approved. If someone could get back to me that would be much appreciated! Thanks in advance and have a great day!

Kirk

Why do you have to switch, both ABS and PVC are approved for residential in US. Yes, you can use a threaded adapter, one male and one female to make the transition. Not sure its approved everywhere, but there is a multi-purpose glue that will join ABS and PVC.

You said you were "told" you must switch, why not check with building authority.

Hi everyone...

Best choice in this case will be to either install ABS male adapter (see 1st pic.) to PVC female adapter (see 2nd pic.) and go from there... or you could use a 3" plastic to plastic shielded clamp to make the transition (see 3rd pic.). Do not use the unshielded fernco clamps (see 4th pic.) or the no-hub clamp (last picture... crimped shield).. these are illegal clamps for this application!

They also make a ABS to PVC transition cement (see picture), but this is only supposed to be used to transition between the two plastics UNDERGROUND and only with permission of plumbing inspector.

You cannot use the all purpose cement mentioned above by Hkstroud (not your fault Harold...I had to call oatey to be absolutely sure here... ;))! Oatey states that this is a multipurpose cement but it cannot be used to transition between different plastics... a few reasons for it, such as different expansion/contraction rates and fact that code will simply not allow dissimilar plastics to be joined by solvent weld processes... except for the underground exception mentioned above... ok?

Anyway, use the male and female adapters mentioned or use the shielded clamp... these options will pass inspection in any state!

Let us know if need more info...

MARK