Bought my first house last year. 1957 single story ranch. Inspector missed this, but i noticed early on that this pipe hanger had come loose (and been poorly resecured) causing a ~6 foot run of the waste pipe to pitch slightly in the wrong direction.
Everything was draining fine and nothing was leaking when we moved in so I left it that way for a while. Recently had a clog in the bathroom sink and had to snake all the way down to this sagging joint to clear it, so probably time to do something about it if I can.
My thinking is to use a bottle jack and a 2x4 to slowly jack up the sagging joint and secure it with a sturdier strap. Probably don't have the space to get it to 1/4" per foot, but should at least be able to get it sloping in the right direction. The branch lines flowing into that run have some extra slope to them, so I don't think it will cause an upstream issue.
Mostly worried about cracking the cast iron. The pipes are almost 70 years old, so I'm aware that this would be a temporary fix at best, but I aim to get as many years as I can out of the current plumbing before considering replacement. If there's an obviously better solution, I'm all for it.
