What type of interior wall?

[cmwm]

Hello!

What kind of interior wall is this? Like a dark gray sand-like material. Is it some form of lightweight concrete? The wall is only a thin partition and sounds more like plasterboard when you knock on it.

Would it be possible to mount a relatively heavy string shelf on this material, and if so, what kind of plug and screw should be used?

Thanks in advance!

 

[BirgitS]

Does it concern the multi-family house from 1936?
Then it could be slag brick with plaster. See here: https://sv.wikipedia.org/wiki/Slaggtegel
I think you can check what is recommended for brick walls: https://duckduckgo.com/?t=ffab&q=skruva+i+tegelvägg&atb=v165-1&ia=web
But heavy things on such a wall are not really the best idea.

 

[cmwm]

Exactly, I forgot to mention that it's in the apartment from 1936! Thanks for the reply, I'll read up on slaggtegel and possible mounting options. Might need to rethink the shelf!