Flange Extension Question

Hi I am a new homeowner, and before I start moving in, I decided to tile the bathroom floor. Prior to tiling the floor, I have removed the toilet, and cleaned the flange removing the old wax ring.

The old flange is cast iron, and from what I see, it is in good condition. However, it sits about 1/3 below the new tile floor & backerboard I have installed. I have purchased a flange extension kit, and am preparing to reinstall the toilet.

The problem I am having is this: the screwholes in the flange extensions do not match the screwholes on the cast iron flange, and I am not able to screw the flange extensions to the flange. Is it okay to just apply the adhesive to the flange extension & flange, or will this cause a problem down the road?

Thanks for the help!

If you are going to use the flange bolt slots in the CI flange and can do it through the extender, sealing the extender to the CI should work fine to minimize the required wax buildup. Don't expect the toilet to be anchored properly if you use the slots in the extender if it isn't screwed down to the floor or the flange.

I'm not familiar with flange extensions -- what forms the seal between the original flange and the extension? Is there a gasket or some wax in there?

Just drill holes thru thr flange extenders where you need them. Use caulk or a thin schmeer of wax between the cast iron collar and subsequent extenders to form a good seal.