I am in the process of trying to mount a shower riser on a tiled plasterboard wall. I bought some fisher Plasterboard fixings, but having experimented with a scrap tile and piece of plasterboard have come to a halt, the fixings require a 6mm hole in the plasterboard, but to get the head below the tile will require a 10mm hole in the tile. My experiments seem to show that in drilling the 10mm hole, you damage the surface of the plasterboard, and presumably weaken the fixing?
Is this the best solution or should I be looking at something else?
If this is the best solution where can I get a 10mm tile drill bit, as I don't fancy using a standard masonry drill bit as there seems to be a lot of vibration. I have a pointed(carbide?) 6mm tile bit that drills very well with almost no vibration, but I cannot find something similar in 10mm.
All ideas welcome.