Black mold? Dangerous?

[Bunker]

Hello!

I have an attic here, where you can see some black spots on the ceiling.
I assume it's black mold or could it be something else?

One plank seems to not be affected, I assume it's because it was, for example, kärnvirke or from another tree that makes it more resistant?

I have read a bit about the general problem with attics, is this growth fairly common in our houses, or can it be considered worse than usual in this case?
Should one panic and decontaminate the house immediately, or is it not a major danger and you can tackle the problem with attic renovation + spraying suitable mold solution in a few years?

I'm in the process of buying a house and I found this yesterday when I inspected the house, so I'm wondering if I should proceed with the purchase or hold back.
The house has an inhabited attic, where the side attics seem okay but the space up near the ridge (which only has a height of about 40cm) looks like in the picture. Ventilation is at the eaves and a vent in the ridge.

Thank you very much.

 

[Locke]

It is not possible to assess potential growth from a picture. You can have significant growth without it being visible, and you can have discolorations without it being mold.

If you are concerned, bring along a knowledgeable person and ask for their purely subjective opinion. If you want to know exactly how it stands, take a sample and send it for analysis - that is (apart from the experts here at Byggahus) the only sure way.

 

[Bunker]

Thanks for the response, interesting that it doesn't necessarily have to be anything.

Any idea how this wind compares to a Swedish average? Do most cold attics have discolorations or are they usually without visible changes? It’s a bit worrying to buy a house with a cold attic that looks like this, but if it’s the case that most other houses you could potentially buy instead would also have a similar appearance/problem, then it might not matter much - you need to fix it anyway.

And lastly, where do you send samples for analysis? Anticimex or some government agency?

 

[Locke]

Long-term studies have been conducted on cold attics and it has essentially been found that there is always growth. The aim is therefore to limit the extent.

What often causes problems is when people start to cut openings for more ventilation or add insulation to the attic floor without understanding how this affects the climate up there.

SP, WSP, Botanisk Analys - google and see.