After having replaced ~30' of 4" cast iron w PVC, I'm left with two holes in the cinderblock foundation. The holes are the height of 1 block and about 1/2 the width of a block. These leaves a pretty significant hole around the pipe.
I'm inclined to think I'll need to build a crazy custom form to go around the pipes and be able to access the hole as I work.
But I'm also thinking there has to be a better way.
Both holes have already been backfilled inside from the top. So all work needs to be done on the exterior.
Also note the rubber boot between the PVC and the cast Iron? I've found mixed opinions on the need to surround that with poured concrete. In truth this work (the butt joins not the wall repair) will likely be revisited several years in the future.
Here are pics of both sewer lines. Also note - both lines now have clean-outs and boots. The pic on the second one was taken before that was completed.