ᐅ Garage exterior wall does not dry / plaster does not adhere

Hello

I have a garage wall where the plaster won’t adhere. I’ve tried applying plaster several times, as shown in the photos.

According to the roofer, everything is sealed properly from above. Could the moisture be coming from below? As seen in the photos, the wall is very dry.

How should I proceed?

Thank you

JSavel03 schrieb:

I have already tried several times to apply plaster over it,

Is this supposed to be a joke?
I'm not a plasterer, but first the old plaster needs to be removed. Then you repair the cracks and damaged areas (not sure if epoxy resin is also used here), and after that you apply reinforcing mesh. And you don’t just smear it on. Plastering means applying a thin layer.
Another possible source of error could be using the wrong type of plaster.