I have added a new subfloor to my bathroom and am ready to put some schluter membrane down on the floor before tiling. The old insert to my toilet flange will not come out. I am abte to get an asb 3 to 4" flange into the hole but it now sticks up about 1" above the subfloor height. This could be okay but do I need to get the old insert out? And how? What do I screw the flange into if I cannot? Any help would be appreciated. Thanks Kendall

Not too sure about what you're asking. Are you saying that you'[re going to put a ABS flange over the old flange but want to know what to do with the repair insert in the old flange? Why not use the old flange with a set of flange extenders? It seems to me that would be the easiest way. Let me know what you think. Tom

I had to put 2 1/2" plywood pieces around the opening of my cast pipe to give something for my new flange to screw down into. The old flange was about 7.5" in diameter and sat on top of the plywood sheeting. When I replaced the sheeting the ring broke and the new rings are only about 7" in diameter and the holes in the flange are not spaced far enough apart to reach new plywood. There seems to be some type of insert in the cast which is also creating a problem with the flange seating, hence the 2 1/2" pieces of plywood are screwed through the plywood pieces and into the subfloor to anchor the flange to something. I am concerned that after a finish my floor the flange might stick up above the finished floor heighth.

There seems to be some type of insert in the cast which is also creating a problem with the flange seating,Still trying to understand. What is a "insert" to a toilet flange? Would this be a lead joint? Are you trying to replace a cast iron flange with a plastic one?
the ring broke and the new rings We're not on the same page with terms, What are "rings"? Can you be more specific?
This should be a simple replacement. But I need details and explanations. What was the old flange made of and what are you trying to replace it with? I want to help but I feel like I'm fling blind. Can you shed some light on your problem? Back to you, Tom