Thanks Rob again for the reply!

This is one detail I forgot to mention: I have done a mold test. A swab test in the attic (from the visible mold) and four air samples: three in the house and one outside. There was only one type of mold in the swab test: cladosporum which is a common mold around here (and everywhere I believe). It's not the toxic black mold I believe. And the samples inside the house showed about the same concentration of mold spores as the outside sample (low spore counts).