Hello!
I have just bought an apartment in a building from the 1950s where no major renovation has been done since then. And now it is really needed. There are several questions, but to make it more useful for others, I am creating different questions for the different issues.
The walls are covered with some kind of wallpaper and then painted over with white paint. Naturally, they have been drilled and nailed into. The idea is to fix all this while we're at it and before putting up new wallpaper. In some places, a bit of the concrete has come off in connection with the removal of plugs or glued items, see the picture below.
How do you prepare a hole like this, or a regular drilled hole, to then be filled with a suitable material?
What material is suitable to fill it with?
At the entrance door and behind the radiator, there is no wallpaper, instead, it is probably painted directly on what was previously there. When I removed a piece of the skirting board, large parts of the concrete (or whatever it is) fell off, exposing brick (I think), see the picture below.
What is seen is the floor at the bottom, then a hole, and above parts of the damaged wall
How do I fix such a large hole?
Should I remove more of the concrete that falls off easily before I repair it?
Screw holes and small dents can simply be filled with wall filler. It might shrink a bit when it dries, so just apply another layer.
It's hard to see how big the hole is at the lower part of the wall. In any case, you should remove the loose plaster, at least what you can take off with your fingers without tools. Larger holes can't be filled with wall filler because it dries too slowly, cracks, shrinks, and doesn't hold well. Here, you should use a filler that you mix with powder and water, either type HusFix or plaster. You can apply it in thicker layers, and it's easy to work with.
If you're frugal and skilled, you can also plaster the wall with mortar. It's cheaper than cement filler and plaster filler, but it's considerably more complicated to get right.
