How to fix cracks in aerated concrete indoors

[Andreas121]

Hello!

In our apartment from the 60s, there are a number of primarily smaller cracks. The cracks appeared several years ago due to blasting in the area.
The material seems to be aerated concrete with plaster on top.

I thought I’d fill the smaller cracks with putty, apply paper tape, and then fill again.

When I started working on one of the cracks, it turned out to be larger and deeper, and I’m not at all sure how to fix it.
The crack runs the entire length of the wall and is 2mm wide. See picture.
Can it be fixed the same way?
Should I bring in an expert to look at it?

Thanks in advance!

 

[jonaserik]

Just scrape a little at the edges and apply filler. Since it's lightweight concrete, spray with a plant sprayer so the crack becomes wet/damp first, otherwise, the filler dries too quickly and doesn't adhere well.

 

[Testarn]

I agree with jonaserik, moisten and fill when there are no larger cracks than those in the picture.

 

[Andreas121]

Does the depth of the crack matter?

 

[Testarn]

Does the depth of the crack matter?

As long as there is not a lot of movement in the walls (new blasting, someone throwing themselves against the wall) I would say it doesn't matter. Press it in as far as you can with the putty knife.