Hello Everyone,
Just found this site, while trying to gather info on tackling our plumbing problem. Thought I'd give your forum a try, please bare with me as I try to describe my situation. We own a 1 bath ranch in New Jersey that is mainly Cast Iron & Galvanized Pipes. We plan on adding a second story to this ranch (2-3 years) AND a half bath in the basement (in the next 6 months).

The problem that started this project is the bathroom sink and tub/shower have always drained slowly, even with snaking... So I got tired of snaking and decided to see what was wrong once and for all. I opened the wall behind the bathroom, exposing a 2" Galvanized pipe(2'-6" in length) from the sink to the 3" C.I. stack. After removing the galv. pipe I found it reduced to the size of a nickle from corrosion! I can only assume the piping for the tub/shower is in the same condition and should also be replaced.
The shower ALSO has had no vent pipe...

Do I have to open more walls and install a vent pipe OR does a wet vent come into play here???... There's about 9' of 2" galv. drain pipe from the p-trap of the tub/shower to the main C.I. 4" stack  

The stack is 4" C.I. in the basement, being reduced to 3" C.I. just above the toilet hub and then ran straight up through the roof now as the vent for the entire bathroom.

At this point of replacing pipes... and the planning of a second story, I'm considering replacing ALL the C.I. (3" & 4") with 4" PVC right through to the attic (for when we start the second story).
Any thoughts /ideas on my thinking.

I can take pics if it would help???

Thank you in advance,
Bryan

Hi Bryan,
I can't comment on the venting as I'm no plumbing expert, but I agree that you should replace anything that's not PVC, you'll only run into trouble later if you don't. Also best to do it now before you are relying on it even more with the additions to your house. Good luck with all the work!