I need to cut a circular hole in a ceramic tile big enough for a 15mm pipe. The tile is currently 'not' on the wall as I am chasing the plaster and brick to lay the pipes ready for the shower unit. Any ideas out there?

Thanks!

We have removed sheet vinyl down to bare concrete & will be laying tile. But there is still some chunks of adhesive stuck to the floor.

How clear does the concrete floor have to be before the lay the ceramic tile?