Friends, I am replacing a circa 1975 toilet that is mounted on a cast iron stack with the iron toilet flange. When I pulled the old toilet up the old bolts were just a thread of rusty goop... nothing really there holding it down. THe flange has rusted thru at the slots where the closet bolts should slide in. I have tried to remove the ring and I am stuck. I can see the two straight sloted wood screws that hold the ring down. I am sure they must screw down into the subfloor. When I use a large screw driver to attempt to turn the screws out they just twist apart and strip at the slot. Do you have any suggestions to get the flange freed? I think my subfloor is cement board/blue board on top of plywoord(not sure!). Much appreciation for any guidance you provide.

-ML (PS - the house was built in 1975 and the toilet is original from the builder.)

Seems to me you have two choices. One is to remove the old cast iron flange, possibly by tearing things up to get the old screws out and breaking the connection to the soil pipe or cleaning up what you can and simply adding a steel ring on top of the cast iron. The steel ring is fastened with screws to the floor and has built in keyhole slots for the toilet bolts. This assumes you have solid subfloor to hold the new screws. If you've stopped the source of water that caused the rust in the first place, the steel should be OK. If everything goes well, the new ring should work just fine. Bob.

Yep.. Bob is right... Its called a toilet flange repair ring!!!

Thanks for the feedback. The day after I posted this entry I found a flange repair kit at the local Ace. It was a two piece part that slipped under the old rusty ring. The kit worked great! The new toilet installed just as directed once I had that resolved. This was just one of many unplanned issues I had to deal with to get my bathroom remodel done. Now I know what to expect for next summer's project in the other bath. Thanks again. I like this board a lot ! -MD