Toilet drains into the copper drain.
Looks like someone long ago tapped the drain for a small port (dehum or whatever) and now the current owner doesn’t know how to “seal” it. Zip lock to the rescue…
Copper DWV… gotta be 1960ish construction? I see those every once in a while and figure if the meth heads knew there was that much copper in a house they’d probably break-in and steal it.
Still used in Chicago until 1990.
Very often? An old Oregon plumber told me it was only used in the 60s during the Vietnam war when all the steel was being used for airplanes and ammo. I really don’t see too many houses with it even in the 60s.
The unions are strong in Chicago. They claimed cast iron and copper DWV drains were more fire resistant than PVC. The price was 3X that if a PVC house. I was still installing cast iron lead and oakum with copper DWV well into the late 90’s in Chicago.
My brother owned a home in NW Chicago Burbs that was built in the 1980’s that had all copper drain pipes. I remember in the unfinished basement there was a 4" copper drain pipe that was about 40 feet long that ran from one end of the basement to the other.
I also remember hearing exactly what you’re saying that the unions were very strong, still are, and all plumbing pipe had to be copper.
Same with electrical in Chicago area, no NM Romex, everything is in conduit.