(Ytong) and have deliberately used 36cm wall thickness instead of the planned 16cm between our bedroom and the children's room
The problem is that Ytong with its bulk density < 0.7 is simply not suitable for such applications. And for reasons of youth protection alone, I would never plan parent and children’s bedrooms wall to wall. As already mentioned, drywall in front of the Ytong, plasterboard twice, rather three times, and insulation behind it. Make sure that the stud frame has no direct contact with the Ytong wall. Possibly consider this on both sides of the wall.
Possibly consider on both sides of the wall above.
So something is definitely off there. You can't seriously be working towards a wind load equivalent to half a meter (wall 36 + plaster + studs on both sides + 2/3 layer of sheathing.
There are sound bridges or similar present somewhere.
As I said... the ceiling is about 2:60 high. Above that the roof structure made of wood. Towards the top then a vapor barrier and above that a layer of insulation wool (cold roof). Below gypsum board on aluminum rails.
The collar beam layer is your sound bridge - you don’t need to mess around with the 36.5 cm Ytong for that. Which I consider "slightly" misused for an interior wall anyway...
A bit of bed sports noises haven’t permanently traumatized any child yet. The Mongol is pimping in the yurt, everyone next to him is cracking too, that’s just part of it.
