I'm adding a room to the house that requires footers. In the course of digging the footers I found my sewer line. Not a problem except that it is Orangeburg style pipe (tar paper tube). Before I build over it, I want to replace that section then eventually replace the whole line to the street. Here's what I know: Inside the house I have 3" copper DWV. It extends 2' foot outside the house where it is connected to 4" cast iron with what appears to be cement sealing the 3"-4" connection. Two more feet and I have a CI 90, a CI CO then it transitions to Orangeburg using a thick nohub band made of the Orangeburg material. Then Orangeburg for 40' to a CI 90, then more Orangeburg. The Orangeburg to CI connections are using Lead. I'd like to replace the first 45' (to the CI 90) with PVC. I've purchased a threaded copper adapter that I can sweat onto the 3" copper at the house and a PVC threaded coupler to attach to the copper threads; then a 3-4 pvc adapter. I plan to follow the same path and keep the same grade with the pvc. I guess my concern is the PVC to cast iron connection at the turn. I've read some of the other postings and connecting pvc to cast iron seems to be a real problem. Maybe it would be better to remove the CI 90, replace it with PVC 90 and connect the orangeburg to the PVC? Any input would be appreciated. This only has to last 9 months then I'll replace the rest of the line with PVC.
johnsok

Good morning John,
" I've read some of the other postings and connecting pvc to cast iron seems to be a real problem."
Not on this site you haven't. If this were my job I would convert to PVC at the house and run it all the way but If you wish to co-mingle PVC and Cast Iron I can find no fault with that. I have "married" PVC and Cast Iron with lead and oakum joints, No-Hub Bands and Duel-Tite Rubber Gaskets with no problem or callbacks. I would be interested in hearing the reasoning behind advising against co-mingling PVC and Cast Iron. Regards, tom

Thanks for the response Tom. I'd like to replace the whole line with PVC, but the line runs parallel under my asphalt driveway. I plan to replace the asphalt with concrete in a few months. When I start the driveway project, I'll replace the rest of the line. My reasoning for not wishing to comingle PVC and cast iron is that I have no experience with Cast iron. I'm not a plumber, but I can sweat copper joints together and cement PVC together. Oakum and lead seems old school, but then so is cast iron. I remember as a kid (40 years ago) watching some plumbers putting together a sewer line for a new church being built across the street from my house. They had a heater, pot, melted lead and collars around the cast iron pipe that they poured the liquid lead into. I didn't know about the Oakum until just recently. Funny I remember that. I don't have the tools for leading. You mention duel-tight rubber gaskets. I was hoping that maybe there is a rubber gasket/O-ring that I could slip over the PVC, push the PVC into the cleaned out Cast iron bell of the 90 and then push/tap the gasket into the bell sealing the connection. This would be something I could do with the tools I have. Any thoughts on that?

Ken

Hey Ken,

" Oakum and lead seems old school, but then so is cast iron. I remember as a kid (40 years ago) watching some plumbers putting together a sewer line for a new church being built across the street from my house. They had a heater, pot, melted lead and collars around the cast iron pipe that they poured the liquid lead into. I didn't know about the Oakum until just recently."

And I was one of the plumbers out in construction that were putting in drainage with lead and oakum joints when you were a kid.

"You mention duel-tight rubber gaskets. I was hoping that maybe there is a rubber gasket/O-ring that I could slip over the PVC, push the PVC into the cleaned out Cast iron bell of the 90 and then push/tap the gasket into the bell sealing the connection. This would be something I could do with the tools I have. Any thoughts on that?"

Lotsa thoughts Ken, Duel Tite connections go like this. You first insert a Duel Tite Gasket, (see image) into the hub of a cast iron fitting. Next you paint the inside of the gasket with Duel Tite Lubricant and file a bevel on the end of the PVC pipe so it will slip in and start to seat. Now paint the pipe and insert it into the gasket making sure that it goes in straight and not cocked. If there's a problem getting it started it's acceptable to take a knife and trim the first few ridges off the front of the gasket. Now simply place a Johson Bar, (And I'll bet you thought a Johnson Bar only lived in your trousers) on the end of the PVC and push it in until it seats. And now you know. Good luck, Tom