I am remodeling a bathroom, removed toilet saw wax ring removed wax ring saw cast iron pipe in floor raised up about a quarter inch above floor two rusted bolts that were screwed into cement floor to hold toilet down. I should mention that I have now removed the tile on the floor.The toilet had been on the concrete and tiled around , so that the toilet was below the level of the tile. The cast iron soil pipe has a rounded edge that is a quarter inch above the cement. The soil pipe is four inch. There is no flange .So Question one assuming the flange must be level with the new floor what is the best type of flange to use I would like to use something that fits inside the soil pipe? Question two will a flange that fits inside the soil pipe require me to remove concrete from around the soil pipe. Question three can the flange be screwed into the cement to hold in place around the soil pipe if so with what? I am using flooring that installed will bring the floor up to flush with the top of the soil pipe as things are now. Question four how much room should there be between the new flooring and the flange ? Please help wife tapping her foot.

I would suggest for you to go to a plumbing supply and ask for a flange that will fit into the 4" cast iron pipe. There are couple of flanges that will work. I like the one that fits inside and it has 3 screws that when you tight them, it compresses a gasket against the cast iron pipe, then you can use some concrete screws from home depot. This screws are about 1inch and a quarter and come with the concrete bit and are blue color. You will need a good drill (hammer drill better) ONce is secured, you can lay the tile as close as possible to the flange. Good luck.

How about a 4" Cast Iron Flange that needs no caulking and fits inside of the 4" soil pipe without having to chip around the pipe? (see image) Check it out at; C40-420 FLANGE CLOSET CAST IRON 4IN X 2IN NO CAULK (http://www.idealtruevalue.com/servlet/the-170944/Detail)
You may secure the flange to the floor using plastic inserts and wood screws or Tapcons. Good luck, Tom