ᐅ Basement wall / granny flat damp? Identifying the cause.

Hello everyone,
we have purchased a house with a basement apartment. At first glance, everything looked fine. Now that we have removed the baseboards and unscrewed the electrical outlets for the painter, we noticed something.
Under the baseboards, the area is blackened and one outlet is rusting (see pictures). I suspect there is a moisture problem.
I can easily imagine that this might be caused solely by improper ventilation. It is also evident in other places that the previous owners did not ventilate properly. However, it could of course also be coming from outside or below.
On the internet, tradespeople often warn against unnecessary basement waterproofing.
What do you think? Should we consult an expert or a building inspector?

Regards and thanks

Hello,

rossivc schrieb:

We bought a house with a basement apartment. At first glance, everything looked fine.

So, you bought it without professional support.

rossivc schrieb:

What do you think? Should I consult an expert/inspection authority?

Consult a specialist with proven experience in masonry and moisture damage. You can find professional support near you at bvfs.de.

Regards, Bauexperte