Is this bluing?

[Berkelus]

Newly built cottage/shed since last fall. I think it's just bluing, but I think it's starting to look a little too dark?

Pictures show the roof. The cottage is not insulated (only windproof fabric) and there is plenty of ventilation.

 

[Matti_75]

Mold

 

[Berkelus]

Mold

What makes you lean towards mold? The roof is sealed, and other wooden parts have the same growth that doesn't belong to the roof.

Are antifungal agents and painting the solution?

 

[Plupp 433451]

What makes you lean towards mold? The roof is tight, and other wooden parts have the same growth that doesn't belong to the roof.

Is it mold poison and painting that are needed?

mold..
the fungus attack is clearly visible.
If it is just dry, this will disappear on its own.
moisture breeds mold..
airy and dry kills mold..

 

[Matti_75]

The mold has resulted from the humidity being too high. It is a very common phenomenon. The boards that have been affected the worst have gotten earth on them when they have been lying against the ground or similar.

 

[TechChad]

If this is mold, is it a problem and should one replace the boards? Or can they be left as long as the conditions are worsened for the mold so it dies?
Is it common for this to happen when building?

 

[Matti_75]

If this is mold, is it a problem and should the boards be replaced? Or can they be left as long as you ensure that the conditions for mold worsen so it dies?
Is it common for this to happen when building?

There are products to kill the growth so that it can be painted over.

 

[useless]

Since it's only a few boards, I wouldn't be particularly worried. If the conditions were bad, all the boards would show signs of growth. Brush off the worst and move on...