I'm installing a new bathroom in my basement with a concrete subfloor I will be laying tile down as well. My question is when I install the toilet flange do I install it on top of the tile or do I need to leave some concrete exposed to attach the flange? Also what would be the best method to attach the flange... glue? Concrete screws? Thanks for any advise you can give.

I just did this and used a expansion anchor in the slab and mounted the flange on top of the tile. Hardest part was drilling the tile and slab, piece of cake after that.

I'm installing a new bathroom in my basement with a concrete subfloor I will be laying tile down as well. My question is when I install the toilet flange do I install it on top of the tile or do I need to leave some concrete exposed to attach the flange? Also what would be the best method to attach the flange... glue? concrete screws? Thanks for any advise you can give.
You install the flange on top of the tile. Unless the flange moves after it's installed there's no need to tie it down.
Good luck, tom

I agree with Tom 100% of the time and "on top" is just fine. However that is the high end of the range and the flange can be flush with the tile surface also and still make a good seal with one wax ring. Can we assume you are using PVC and will glue the falnge to the drain? That should do it.