Painting utility room with gypsum plaster - Which color?

It is possible that the silicification of the silicate paint causes stresses in the plaster that can lead to cracks.

Are cracks in the plaster (immediately after plastering) actually a defect that should be complained about? We have two places in the utility room where elongated cracks appear, mainly where downpipes have been covered. Is that normal, or should I talk to the site manager about it?

Did you sand your Gipspjtz beforehand?

No, but I just noticed it's about gypsum plaster, I overlooked that. We have lime-cement plaster.

Did you sand your gypsum plaster beforehand?

Yes. I sanded everything beforehand and filled in holes.

Are cracks in the plaster (right after plastering) actually a defect that should be complained about? We have two spots in the utility room where elongated cracks appear, mainly where downpipes were enclosed. Is that normal, or should I talk to the site manager about it?

I also have a crack because the "slot" for the downpipes wasn’t properly enclosed. I will address it. You should do that.

We have now had various painters in the house to get quotes. However, we will do the side rooms ourselves. The result is not that important to me there. In the utility room, laundry room, and a storage closet, we will also not have any fleece applied, painting the wall directly will be enough for us. However, we were told that we still have to sand the walls. Not to smooth out every unevenness, the gypsum plaster in these areas is already smooth enough for us, but because supposedly nothing would adhere to the walls otherwise. I had never heard of that before and wonder if it is really necessary.

but supposedly there was nothing on the walls. I hadn't heard anything about that so far and I wonder if that's necessary.

I have rather read that the plaster just soaks up everything. That which does not stick, in the sense of coming off again, I haven't heard of. I would have thought that with a primer or something it would be fine. Or you just need one more layer of paint.