Some questions for you material gurus!

[nikasp]

Combine by tapping and measuring between the hits you get, and you can figure out whether it is solid and regel or not.

 

[thomasx]

The magnet trick assumes that there is no particleboard or OSB behind the plasterboard, because then it doesn't have to be screwed into the studs. For most purposes, it doesn't matter since you can just as well screw into the board, but for this purpose I'm not sure if it will hold. There are significant forces when tensioning a cable.

If there's a wooden board behind, then a type of molly will hold perfectly fine.

 

[Nancy Biäng]

How do you mean then, Thomas? Could it be like concrete-stud-wood panel-gypsum? I thought it was concrete-wood-stud-gypsum? Soon I'll tear a hole in a wall just to know how my house is constructed :s It will probably be when I renovate the living room, because there I have a section equivalent to a gypsum board, which bulges out... feels a bit daunting to start pulling at it...

 

[Christoffer85]

Loosen an outlet and you'll see how the wall is constructed.

 

[thomasx]

What do you mean then, Thomas? Could it be like concrete-rule-wooden board-gypsum? I thought it was concrete-wood-rule-gypsum? Soon I'll tear a hole in a wall just to know how my house is constructed :s It will probably be when I renovate the living room, because there I have a section equivalent to a gypsum board, which bulges out... feels a bit daunting to start pulling at it...

Well, I was thinking, or rather f91jsw was, about the case where there's a wooden board of some kind directly behind the gypsum board. Those of us who build for ourselves often do this just to get a good wall to screw into. But I think this is quite rare otherwise.

What surprises me a bit now, though, is that you mention concrete. Do you have concrete in the walls? If so, that's fine, then you make the mounting in the concrete instead, through the gypsum and into the concrete.

What kind of house do you live in? What is the facade of the house?