I am working on our upstairs bathroom and plan on moving some of the fixtures around to a different side of the room. This means I need to make changes to where the drain comes into the stack (I want to bring it in lower than it is now).
How do I go about replacing a section of 85 year old cast iron pipe? Can I just replace the section I want to change with PVC and tie back into the original cast iron above and below it? Or do I have to replace everything above it with PVC as well (it runs up through the attic and the roof)?
I hope I don't have to replace the entire stack with PVC (I am not sure the new PVC pipe would even fit inside some of the walls as I think the PVC flanges are larger than my cast iron pipe's).