Cast Iron/Galvanized Drain Lines?

[stateliner]

I'm looking for help on identifying what type of drain lines I'm dealing with. I made a successful repair today on one branch, converting what I believe to be cast iron with leaded joints to PVC. Tee fitting off kitchen sink to vent stack had completely corroded thread and drain was backed up so water was reaching that joint and pouring over to basement. Pipe changes appearance in basement so don't know if it goes from cast iron to galvanized?... Based on the appearance of the 4" main line I'm anticipating having to do more conversion to PVC so just looking for advice.

 

[pasadena_commut]

When was the house built? That will give you some clues about which plumbing technologies were in use at that time.

I can't say much more, other than the order is unlikely to be upstream to downstream cast iron to galvanized, but rather the other way around. That is how it is in my house, built 1957 in Southern California. The 4" pipes (there are two drain lines which merge in the middle of the yard and then go to the city's pipe under the street) which go out through the foundation are cast iron, and everything above them is galvanized. Originally just past the foundation each hooked into clay pipe, but part of that had to be replaced with plastic so that a clean out could be installed.

 

[stateliner]

Thanks for the reply. House was built in 1955 and its a ranch 1 bathroom, so I just have one main 4" branch coming from there merging with 2" branch coming from kitchen sink right at basement penetration. Does your drain piping have hub/ leaded joints or threaded? Curious...

 

[havasu]

I saw some lead and oakum connections. Honestly, your best bet it to gut it all, as far as you can, and replace with abs/pvc.

 

[stateliner]

I saw some lead and oakum connections. Honestly, your best bet it to gut it all, as far as you can, and replace with abs/pvc.

Yup, I guess that'd mean going from these joints all the way back...oof that's a big project

 

[pasadena_commut]

Does your drain piping have hub/ leaded joints or threaded? Curious...

Not threaded. Looks a lot like your pictures. Never poked around in the junction looking for lead. The only time I have set eyes on them was when I was under the house for other reasons and saw them in passing. We had a plumber tear out a section of the clay pipe outside the foundation to put in a plastic cleanout. That new plastic (ABS) was attached to the end of the CI pipe with a Fernco connector. The cast iron was somewhat fragile, but the part I could see inside was in good shape, maybe a little rust, still pretty much wide open inside.

 

[waternwavs]

I'm looking for help on identifying what type of drain lines I'm dealing with. I made a successful repair today on one branch, converting what I believe to be cast iron with leaded joints to PVC. Tee fitting off kitchen sink to vent stack had completely corroded thread and drain was backed up so water was reaching that joint and pouring over to basement. Pipe changes appearance in basement so don't know if it goes from cast iron to galvanized?... Based on the appearance of the 4" main line I'm anticipating having to do more conversion to PVC so just looking for advice.

Pic

tempFileForShare_20241122-181005 (1).jpg​

stateliner · Nov 22, 2024 at 6:29 PM looks like galvanized. If the piece that goes up is "vent" - leave it. Anything below that has drain water flow thru it should be ripped out. They corrode form the inside-out. The pic with the cast in the basement - if it isn't leaking, leave it. The cleanout looks intact but you can knock it out and look inside. Replace it with an expandable rubber plug. Good luck

 

[MicEd69]

What was the condition of the cast iron that you removed? If it was not thinning and not rusting from the outside and if the joints were not leaking, it will likely remain serviceable for some time. But all the threaded piping is steel pipe (probably galvanized) and should be replaced.