In a rash moment, we chose very hard porcelain tiles for our wetroom walls. Our tilers and builders complained of burning out several diamond drills when working with it. Now I want to fit a mirrored bathroom cabinet to one of these walls. The porcelain is secured to cement board, which is fixed to a stud wall. Knowing the difficulties and thickness of materials here, a cavity fixing seems like a major challenge. I had hoped to find a stud - but my stud finder is just not helping here. I would value any advice on how to fix to this wall. For example, will traditional plugs and screws provide enough load bearing into the cement board, assuming I can drill that far?