I'm trying to put up a whiteboard on a plasterboard wall. I am screwing the holes from one end into a stud, but the other end does not line up with a stud. I therefore planned on using wallmates. However, when I tried putting a wallmate in, I hit a second board behind the plasterboard.
As best I can tell, it's some kind of wood, quite thin. I drilled through it and tried to put the wallmate in again, but it just won't go and started to pull the plasterboard outwards.
Can anyone tell me what the second board might be (I'm in Australia, if that helps)? It's a study, so wasn't really expecting anything other than gyprock. Also, what fixture would be best?