Crack in balcony slab in 1961 house

Hello dear forum!

A few months ago, we bought a two-family house built in 1961 and are currently renovating it. Since next month the house is supposed to be wrapped in [WDVS], I have already prepared the two balconies (ground floor and upper floor). The original structure was as follows: concrete slab, screed, tiles.

There was no waterproofing on the concrete. The tiles and screed were completely undamaged. When I then removed the balcony railing, tiles, and screed, I saw that both balconies were cracked in exactly the same spot. The crack runs transversely from the balcony towards the house. I stapled the cracks and poured epoxy resin. On the upper balcony, you can see how the resin flowed through the crack. I repaired a few chipped corners with 2-component epoxy mortar. The balconies are already sealed with polymer bitumen membranes.

At the point where the balconies cracked, the steel reinforcement has a rather low cover, almost none at all. Could this be a possible reason for the crack? Or has the house settled slightly on one side and caused the crack?

Should I fear something worse or can the balconies be integrated into the [WDVS]?

I would have that checked – and not by someone who would like to get the repair order...

The structural engineers in the area are unfortunately hard to reach or have no capacity. I have now forwarded the pictures to a structural engineer, let's see what kind of response comes.

The structural engineers in the area are unfortunately hard to reach or have no capacity.

I keep forgetting these aspects. We were warmly welcomed in the village community and are involved. The fact that no one with expertise is ever available actually doesn't exist.

that the two balconies are torn down at exactly the same spot.

If you already suspect an identical cause in the construction, you should also show the classification within the overall picture, i.e., the complete floor plans and the section. Isolated focus zooms are always only seemingly enlightening when outsiders are supposed to contribute diagnoses.