To measure what I was asking about, you would put a long straight thing, like a level, across the gap, and measure down to the top of the pvc from the bottom of the level.
I see you have removed more PVC, so my idea of the repair ring is probably no longer practical.
So lets say you get PVC pipe glued into the remnants of the old flange? What then? What will the flange rest on and attach to
? Do you plan to put wooden spacers in place, or to pour concrete?
For cutting the overhang, a curved rasp might be better than sandpaper, at least for some of the material removal.
I interpret the inside of the opening in that photo as being about ~3/8" of height of old flange fitting, then a short pipe segment ~3", then a (hubbed) elbow. So I would think only that top ~3/8" is obstructing the new inside fit flange.
I agree.
I am thinking that a common 4x3 closet flange was glued inside of 4x3 spigot closet elbow. Is that how you think the current situation came to be? That would explain the 3.5 inch ID. Now suppose that is the case, suppose the PVC removal continued, with possible an enlargement of the hole in the subfloor. Then an outside 4 inch close flange could go onto that closet elbow.
That would be if the horizontal pipe below is a 4 inch pipe, then it could just be a spigot elbow or even a hub-hub elbow with a piece of 4 inch pipe glued in. Each of these ideas would still have PVC down there that could accept a 4 inch outside closet flange.
Pecck, don't start cutting to act on this theory until you get confirmation. If that were the case, there are nice outside 4 inch compression closet flanges that can go to various depths.
Plumbest or Code Blue outside compression closet flanges:
C40420* 4 pipe x 2 depth
C40430* 4 pipe x 3 depth
C40440* 4 pipe x 4 depth
Compression means no glue. Easy do-overs.