Cross stud is in the wrong place so can't fix to that. The cabinet is large and the ceiling is sloping (attic) so I'm restricted in where it can go. I can see a cross stud but it's not wide enough - when I marked the screw holes the screwdriver went straight through and didn't touch anything. Will toggle bolt type fixings be adequate don't want it too fall off wall with everything in it and break the basin and tiles!!
locate the upright studs and fix to them
You local DIY shop will stock plasterboard plugs, same as a rawl plug but designed for plaster board. There are two types, firstly plastic ones with two hooks the spread behind the plasterboard. Secondly threaded aluminium ones that you screw in to the wall with a Phillips screwdriver. I would recommend the aluminium ones as a bathroom cabinet can be heavy when full. I have used these plugs to put up kitchen wall units without any issues :-)
Spider anchors. Which are a slitted metal tube with a nut fastened into on end of it. You read the picture instructions and follow that. Ask hardware store. There are also large twisy plastic ones which work as well by a different principle. Your choice. Ask the staff there OR Cut out the plaster board and put cross board in lower and reaffix the plasterboard OR Put on a plywood sheet on the wall first and screw that sheet to the cross boards and verticals. Use 3/4 -1 plywood. Then finish it off with a corner moulding all around the cabinet. Each way works. It depends on the amount of work you want to do
I would recommend the expandable hollow wall anchors (page 7 of article) for your application - good luck!
