Walls in the shell construction already affected by moss infestation

OT:
It doesn't seem to be an isolated case that the construction workers always forget to install the water deflectors during the shell construction. We also didn't have any, and out of desperation, we installed them ourselves. Our main contractor then scolded the craftsmen like a fishwife because, of course, delays occurred due to moisture.

First of all, the damage must be documented and an expert must assign the causes – this determines who has to pay for the repair.

Then you need a specialist, who can be found in the directory under "Bautenschutz." Interpreting photos in the forum would be like reading tea leaves and too imprecise here for the "treatment."

Thank you for the reply. That helps me for now.