Thanks again guys, obviously i'm needing something to slip over a standard 4" pipe. The largest ID flanges found at our local "hardware" are 4.5" OD, just like the pipe i'm trying to slip over. That fitting looks like it would fit over a 3.5" (4"od) pipe for what good that does. Everything else in that store is smaller. The first thing the young girl showed me was something to mount a clothes hanger rod in a closet
but she is trying to help. Her father will be back next week and promises to order what ever i need. I just don't know what to call the "conventional" 4" slip over flange?? A "...4" slip over flange"??
Their catalogs don't seem to list anything with a name like that. ??
Try as i might, there just isn't enough slab to screw the flange screws into. Filling the gap with thin set of some kind (epoxy?) sounds viable if there's a way to get the stuff in there after the flange is set. We're planning to mount an ADA toilet and feel like it needs to be anchored pretty solidly. Thanks again for the very useful ideas. All i need now is the right flange.