Can you lay larger ceramic tiles over existing smaller tiles in bathroom on main floor? Prep work needed?

My preference would be to take up the old tiles first, but here is a website explaining how you can put ceramic over ceramic.

www.onlinetips.org/installing-over-tile

It all depends if they have a rough texture its worth a try but if they're smooth and shiny (best way to describe it) then its probably not going to work
But I'm not too sure
You can always try tiling over somewhere that won't be noticed easily and see if it does :D

A few of problems u will have when going over existing floor tile.

1. Will have to raise toilet flange.

2. Will have to raise marble saddle at door/doors.

3. Will have to cut bottom of doors/doors to clear marble saddles.

4. If doing under vanity (recommended) will have to redo waste line.

More labor to remove existing and dustier but less problems with items listed above.

Chuck