Hi!
We have bought an apartment from 1930 that we are renovating. The walls currently have wallpaper, and underneath there is either:
Brick, mortar, and then some sort of paperboard
Cross beams with some kind of mortar and reed
The goal is smooth walls, and it would obviously be good if it’s as easy as possible to screw things in. Just applying putty feels risky that it might not adhere/crack, right?
Or is it easier to install renovation plasterboard?