: I'm re-modelling my bathroom. I plan to replace the toilet, etc. I plan to tile over the existing tiles. My questions are, do I tile before or after I fit the toilet etc, any problems I should look out for tiling over tiles.

: Thanks, Ken

Ken,
The tile goes down first, then the toilet sets over the tile. Caulking goes around the front of the toilet, from bolt to bolt, leaving none behind.
If the seal leaks, you will want to know before the flooring rots out.