I'm deciding whether to repair or replace my ancient cast iron DWV plumbing while the walls and ceilings are open.
The 1.5" steel shower/tub drain is currently notched through joists for a run of about five feet, incorporating a long trap, through three joists. I neither want to drill more holes in the joists nor use a drop ceiling, nor remove the beautiful marble floor above. The replacement will be in place.
My question concerns threading 1.5" PVC through the existing holes: I'm assuming I'll have to assemble from sections. Is it terrible to introduce couplings to a PVC drain, or is this very common and I shouldn't worry?
Would there be any benefit to using copper? Or some other material?
I might prefer to keep the steel if rodding would get it all the way clean--it's close to solid crud inside--any relevant experiences helpful here.