Very clever, especially if the attic space is not a heated living area,...
So before you come here with such arrogant comments, let me clarify something for you:
Our plastering was done in December last year. The screed was laid in mid-January. Until then, we had no problems. Now the screed layer installer told me that we shouldn’t walk on the screed for 7 days and that all windows should be kept closed during this time. Said and done.
After 7 days, I went into the attic for the first time (which is supposed to become living space by the way and has underfloor heating, which however was not operational until three weeks ago) and then discovered these stains. We then set up a dehumidifier, which has been running for almost three weeks. Since then, the stains have not gotten any worse.
When I asked the roofer about the stains, he was flabbergasted, because he totally disagreed with the screed installer’s statements regarding ventilation. But that’s how it is in construction: You ask ten different people and get ten different opinions.
In any case, both the roofer and my architect (who only designed the plans and is not managing the construction on site), said I shouldn’t worry about the stains. These are only surface spores which can be removed with high-proof alcohol or a mold remover.
However, before I smear the wood and the roofing underlay with chemicals, I thought I would get some constructive suggestions here and thus be able to verify the statements. Luckily, some people are taking my inquiry seriously. Thanks for that!
