Filling larger defects in basement walls

Hello everyone,

our construction is progressing well, so that one can slowly start thinking about this or that job for "later" or "in between." Specifically, we are handed over the basement with raw walls (filled precast concrete parts). Presumably from the crane assembly, some wall parts have the shown metal inlets. Of course, these should be plastered over eventually. The question is only with what? Simply fill the hole with putty until it’s full, or does something firmer need to go underneath to roughly fill the hole first and then only thinly coat it with putty?

Regards

Daniel

They will probably be auxiliary rooms. In this respect, use a ready-made ready-mixed filler (3kg bucket from the hardware store). Simply fill, lightly moisten the surface beforehand. Depending on the size of the hole, maybe do it twice and then sand smooth -> thing done

Sure, a mirror-smooth paint surface is not planned there. What I don't know: Does regular filler even hold in the indentation because of the metal? And can filler be applied 2cm thick or will it all crumble out later?