A leak developed in the main cast iron vertical stack of pipes leading to the horizontal main drain. Unfortunately, for me, the leak was so close to the ground that I had to break the concrete slab of the house. At that point, it just made sense to dig an extra 4 inches or so and remove the bad cast iron pipe to the horizontal pipe hub connection.

My question is, can I use a pvc pipe to connect the horizontal cast iron stack to the vertical cast iron stack? I was told by a guy at the plumbing supply store that this did not meet code in NYC, New York. Is this true? At this point in time, isn't the entire plumbing system of a house constructed with pvc pipe? Keep in mind that the section of pipe I want to install extends 4 inches below ground to about 4 inches above ground. These are all internal house pipes. Thanks!

Hey Coff...

To make this legal all you should need to do is to install a shielded transition clamp similar to the one I have posted a picture of.

This style of clamp is ordered in such a way that it acommodates the difference in pipe size between 4" cast and 4" pvc. You would order a 4" cast iron x 4" pvc plastic mission or proflex shielded clamp. Then you would use a LONG SWEEP 90 degree elbow to come out of the ground and also, install a 4" dandy cleanout (required at the base of all plumbing waste stacks.. see picture).

Also, you need to note here that if you are messing with a vertical stack that you will need to support that vertical stack before you cut into it. I recommend that you purchase a 4" riser clamp (see picture), attach to pipe and then support the vertical load by installing 2"x4"s under each wing of the riser clamp. Not to be a bummer, but people have died not supporting the vertical stack properly... never mind the property damage that can happen!

To cut into the stack or the pipe can use a sawzall with diamond sawzall blade or carbide sawzall blades...or you can rent a ratchet snap cutter.

Anyway... let us know if need more information here... glad to help...

MARK

Here is a picture of how to support the vertical stack properly/safely. Could even bring the riser clamp higher to just under the cast iron hub if you wanted.