I am going to install a toilet in the basement that already was rough-in when the house was built.
I have a cast iron pipe for the toilet sticking out about 10". I am going to install ceramic tile on the floor, do I cut the pipe down to the concrete floor and install the flange and butt the tile up to the flange so they are about the same height or do I set the tile up to the pipe and install the flange so it sits on the tile. Or should I be doing this differently. Thanks for your answers

The top of the flange should be flush with the finished tile floor.

I am going to install a toilet in the basement that already was rough-in when the house was built.
I have a cast iron pipe for the toilet sticking out about 10". I am going to install ceramic tile on the floor, do I cut the pipe down to the concrete floor and install the flange and butt the tile up to the flange so they are about the same height or do I set the tile up to the pipe and install the flange so it sits on the tile. or should I be doing this differently. thanks for your answers

You can do it either way.

However, it will be much easier to fasten the flange to the concrete than it will be to the tile.

What you want to use is called a 'Torque Set Closet Flange' (http://www.plumbingworld.com/drainsandflanges.html).

If you decide to go this route, you will need to use a chipping hammer to take out enough concrete around the C/I pipe to accommodate for the lower part of the flange.

I usually dry set the flange after chipping out enough concrete and then scribe a line flush with the top of the flange around the pipe, remove the flange and then cut off the excess C/I pipe with an angle grinder outfitted with a diamond blade.

Growlers technique of measuring and cutting the pipe will save you time. The earlier post concerns me or I have just installed several hundred flanges incorrectly. The underside of the flange sits flush on the finished floor.

Hey ballenger If you've been installing them wrong then I have too guess maybe we've just been lucky huh.

Well... you learn something new every day. Luckily Growler says either way works because I've always done them flush.

One more time guys! All a toilet flange does is secure the bowl to the floor. The wax seal prevents leaks. Growler's correct. The flange can moumt on the sub floor or on top of the tile and still secure the bowl to the floor. The wax seal will take up the difference and prevent sewer gas and leaks from occurring. Good luck, Tom