Plaster interior wall, fix plaster detachment?

[knoen]

I have an interior wall above ground where the plaster has partially come off that I would like to repair. The house was built in 1947 and I am wondering which type of plaster mortar is suitable to use so I can blend it with the existing one?

 

[Plupp 405730]

I have an interior wall above ground where the plaster has partially detached that I would like to repair.
The house was built in 1947, and I wonder which plaster mix is suitable to use so I can match it to the existing one?

Is it lightweight concrete Siporex, a bluish variety of the stone itself under the plaster?

 

[knoen]

Is the lightweight concrete siporex a bluish variant, the stone itself under the plaster?

Don't really know but maybe thinking it's blåbetong🤔

 

[Drburr]

Don't really know but maybe thinking blue concrete🤔

Stick the knife in it, if it's soft it's lightweight concrete.

 

[BSOD]

Looks like some form of cellular concrete/lightweight concrete/blue concrete. In that case, low-alkaline plaster is usually used.

I've only plastered on concrete/leca and similar, so I don't have much insight into the low-alkaline products.

Weber or Finja's website surely provides good answers when you know what the substrate is. Reading their systems and construction suggestions is my tip.

 

[knoen]

Looks like some form of gas concrete/light concrete/blue concrete. You typically use low-alkali plaster.

I've only plastered on concrete/leca etc., so I don't have much insight into the low-alkali products.

Weber or Finja's website will surely provide good answers once you know what the substrate is. Reading their system and construction suggestions is my tip.

It's on the inside above ground, so my thought was to use c-plaster, but maybe that's wrong, there is kc-plaster mortar, maybe that's better?