Interior walls: gypsum board or OSB board?

I don't want to focus the discussion so much on the humidity, rather what you think about the different wall constructions.

Both options are OK, you can't go wrong there. We decided on double Fermacell in front of the installation layer.

The OSB variant simply has the advantage that you can easily "spax" things to the wall.

Oops! Okay, how does that work with the plaster version then? No Spax :eek:

There are two types of anchors for gypsum walls. One screws itself into the drywall, the other expands behind the gypsum wall. The latter also holds a considerable weight. You can quickly find [Gipswanddübel] using the search. "Spaxen" is faster and easier but can cause the hole in the gypsum wall to fray.

Are those special screws that need to be screwed in there, or can you also use Spax?

Are those possibly the same variants as for a [Rigipswand]? Then I actually know both...

Is that somehow problematic regarding the insulation if you don't have a separate installation wall but the thermal insulation starts directly there?

Did you see the "sister thread"?
https://www.hausbau-forum.de/threads/holzstaenderbauer-ersetzt-osb-durch-gipsfaserplatten-gleichwertig.41059/