Fixing to double-tiled plasterboard hollow wall

[Clanger]

I've just tiled over tiles in a bathroom. The original tiles are on a plasterboard hollow wall. The newer tiles are thicker than the others.

I now need to fix a shower riser to the wall, but I'm having problems considering the best fixings. The "usual" ones are not deep enough to toggle through the thickness of two tiles and plasterboard, and I can't find anything with a deep enough barrel that would do the job.

I don't particularly want to use the metal spring toggles.

Anyone got any ideas ?

Thanks.

[kbrownie]

Clanger, have you tried hollow wall anchors?
KB