Cast iron vent

Hey Folks,

We had a sewage gas leak, so I pulled of the toilet and opened things up. Here you see the toilet vent cracked, which goes back into the wall and up (the sewage line goes down). It is very tempting to just replace the cracked section with ABS, and then stitch it all back up. We could also pull out that entire vent going up, but it seems like overkill. I guess the benefit would be to replace it with something that weighs less.

Another idea is we do tons more excavation and replace everything. What are thoughts here? For a little more background, all the sewage lines Out of the house are pvc, which we put in 10 years ago.

Thanks Folks!

sometimes the big ??? Is where do you stop.
How much do you tear out to tie into good pipe.
That sometimes comes with experience and the skill to connect new to OLD.

I would start cutting and you might see that more of the pipe is getting thin or it breaks as you go. Find a solid piece and tie in.

Just be sure the pipe is supported above the cut.

Hey all, that pipe above was not supported at all, it pulled right out. So, we replaced the entire vent with pvc. Also, we tied in the sink vent higher up, since it was really close to the sink line. Working great now! Thanks for your responses!