I'm in the process of installing a new bathroom in my basement here in Milton Ma. The house was built in 1870 and already had a toilet in the basement. After busting up the old concrete and digging up the dirt to prepare for the laying of the various tub, sink and toilet drain pipes, I came to the old cast iron drain pipes and I do mean old. I noticed that the pipe is very old and sad to say broken up as well as the flange, which of course all needs to be replaced. The cleanout, which there are two, are in great shape, here's my question, I want to install PVC throughout, with the exception of the two cleanouts,can this be done, can you attach PVC to cast iron, or do I have to go PVC all the way? Do I have to stay with cast iron ? Please advise. One more question, what about venting, can I set up 2" venting and connect/vent them to a drain line coming from my kitchen upstairs or do I have to go up through the walls, attic and through the roof ? The spacing is very tight through the basement leading to the rough, and it seems that I would have to bust up quite a bit of walls, which I really don't want to. What about installing an Air Admittance Valve "Cheater Vent" that you advised one member or can I vent through the side of the house ? Any advise and assistance will be greatly appreciated. Thanks, look forward to hearing from you.