I need to break up a concrete floor to install and join the plumbing in a 50 year old dwelling. Am I likely to find clay sewage pipes or iron pipes and what precautions should I take?

I think we need to get this moved to plumbing so the actual plumbers can help. I don't do rough in work but Tom, Milo and Mark can help you. Where do you live and do you know if a building permit is required for your work? Breaking the floor and installing a 3" drain connecting to your existing is just a start. You also need to vent this new plumbing so check to see where your current vent stack is located and be prepared to tell the guys additional info.

I need to break up a concrete floor to install and join the plumbing in a 50 year old dwelling. Am I likely to find clay sewage pipes or iron pipes and what precautions should I take?
Unless you have a really old house the drainage will be cast iron A typical basement rough in goes down like this. Toilet connects to sewer main. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim. Good luck, Tom

Hey Gerryrob...

Click on this link.. it starts rough but ends up going through most of what is involved in doing an underground plumbing job for basement bathroom... including pictures!

https://www.askmehelpdesk.com/plumbing/new-basment-bathroom-252241.html

Read up at the post and then let us know if you have any questions...

MARK