Garage base draws water - defect?

That is probably it, normally there has to be a dimpled membrane between the wall and the paving.

That is absolutely correct.

However, I believe that the condition of the substrate (gravel bed) as well as drainage and runoff also play a crucial role here.

It is visually very charming to lay the floor covering right up to a wall.
However, "invisible" (partly elaborate) measures must be in place underground to avoid construction damage like the ones visible here.
In my opinion, a clear construction error was made here. This is definitely *not* "rain splashes." There is rising damp in the wall.

I strongly advise having this properly investigated in depth by construction professionals and to take appropriate remedial measures. And do so before the next winter.

Best regards

Thorsten

Noppenbahn is not a waterproofing, but still often common.

Thesis:

Garage builder says: Waterproofing is none of my business, I don’t know what the client wants to put around it...

Landscape gardener says: Waterproofing is not part of my paving work, someone else has to do it ...

The plan was fixed. Both sides knew where the paving and paths were. In my opinion, the landscape gardener is not responsible for the waterproofing of the garage.

In my opinion, the landscape gardener is not responsible for sealing the garage.

I agree. The problem lies deeper.

I have not yet mentioned that the wall is dry again the next day. If the plaster now draws water from below, does it then dry out that quickly again?

I haven't mentioned yet that the wall is dry again the next day. If the plaster now absorbs water from below, does it then dry out again that quickly?

You can see your own photos, Florian.

This is the west/weather side. Of course, the wind dries the surface moisture.

Normally, however, you never see something like this.

If you don't "get to the bottom" of the matter, you will definitely experience a Waterloo with this.

Please thoroughly, objectively, and kindly get to the bottom of the matter.
It can still be solved quite easily.

If a construction/frost damage sets in, it will become extremely expensive.

I had a really excellent civil engineer who taught me a lot about civil engineering. I even advised neighbors who made mistakes (their developer), and I was able to prevent worse here.

We did everything around my house to avoid such points. I can only give you my amateur advice to protect you from further damage. My goal is not to scare you but to help you. You must (!) take action. Ostrich tactics are out of place here.

Best regards
Thorsten