Plastering and painting concrete ceiling in the exterior area

Hello everyone,

our filigree ceiling serves as a roof for the terrace in the outdoor area. I want to fill the joints here and then paint the entire ceiling. Inside, this was done with Rotband and Uniflott. However, at least Rotband is only approved for indoor use.

Which materials are best for the outdoor area? Which paint is suitable here, facade paint?

Definitely use facade paint.
Putty/plaster, the specialists here can say more about that.
It only concerns the lower ceiling, right? Surely bitumen membrane and such will be applied on top...

Yes, only at the bottom. On top is the balcony with flat roof membrane as sealing.

Ardex B10, for coarse B12; approved for interior and exterior

Actually, any other concrete filler works too, right? Can I sand it with a completely normal giraffe?

I can't think of anyone off the top of my head who is not registered abroad, just check the datasheet. Giraffe is fine