I'm new to this group so be gentle. I'm in new territory here with installing tile in a small bathroom and have got the info about the flange being on top of the finish floor. In my case, I have a brass flange that sits around a lead extension soldered into cast iron pipe. The flange has a bevel and the lead is hammered around evenly to make a beveled opening. Like all modern flanges, should this one also sit on the finish floor? Would it be better to make wood donuts that would raise the bottom of the flange to the height of the finish floor and be securely attached to the subfloor with no thinset, membrane, or tile between it and a secure mount? I also would like to not have to replace all this with PVC, I know I can cut the cast iron and use rubber couplers but the cast iron is in very good shape as is the lead for the flange.