Is the use of no hubs allowed by plumbing code behind walls.

Hey MC61:

Are you asking in regards to residential or commercial application here..

If commercial... no issue at all.

If residential and using no hub pipe and no hub clamps then also OK here (if tested and inspected properly).

If transitioning between different materials... such as connecting cast iron drain pipe to updated PVC pipe... NO HUB CLAMPS ARE NOT CORRECT HERE (see pic. #1)!

Here, you want to use shielded clamps (see picture #2 and #5)... referred to as proflex or mission style clamps to transition properly between different materials (The rubber type sleeve accounts for slight difference in thickness of pipes... kinda cool! ). If tested and inspected they are allowed for sure.

I also like the 4 band clamps (pic. #3)... but not necessarily LEGAL.. ;) Just has more bands for tightening!

The fourth picture (rubber fernco, 2 bands) is not allowed behind walls for any reason.

This all said, if this is remodel, many different things are acceptable.. depending on circumstance.

If not being inspected... all is illegal anyway. If inspected.. well, the inspectors will let you know.

To understand this a little better...you may want to click on this link:

https://www.askmehelpdesk.com/plumbing/1-1-2-black-plastic-drain-pipe-195719.html

Here, IAMGROWLER (see link) gives a great explanation on no hub clamps VS shielded clamps..;)

Let me know what you think... MARK

.