I'm doing new construction, and I want to use cast iron for just the vertical portion of drain pipe that passes through the wall in occupied space so that I don't have to listen to poop rumbling down the wall. My plumber is concerned that there's no reliable way to make the transition between PVC and Cast iron. I know this is a common practice. What educational resources can I point my plumber to so that he understands how to make the transition correctly and can be comfortable doing it?

[www.charlottepipe.com]

quote. "My plumber is concerned that there's no reliable way to make the transition between PVC and Cast iron".

well, lead and oakum joints have been a reliable way of joining pipes together for at least a century. many of them are still in existence today and show no signs of failure.

Doesn't molten lead damage PVC?

Thanks. That might be just what I need to show my plumber I'm not crazy.

I would use a 3" shielded coupling (3" CI x 3" Pl).

the OD on the two pipes are slightly different so the manufacturer of these couplings has compensated for that.
the gasket is a bit thicker on the cast iron side. It's labeled CI and you can also feel the difference.

NP16 may be referring to transition couplings something like this. Perfectly acceptable to transitions from cast to plastic, at least where I work. Wouldn't hurt to verify with your inspector.


[missionrubber.com]

Lead and oakum with pvc spigot, best for the cast iron application. Not done much in my area. Cast iron, the better quality like used in schools and churches are still installed, still working error free to this day with no need for replacement.

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Everything in Plumbing can be repaired or replaced.