The house is 3 years old, recently on the underlayment and the elements of the facade began to appear mold. And both in places exposed to moisture and where it can not get in at all.
Wood, soffits, covered with three coats of alkyd paint with linseed oil, I think just like mold.
The facade elements are made of eps with factory plaster and an acrylic-based decorative overlay with quartz sand.
The gutters are plastic at all, but there is mold on it too. And it is green on the gutter, and black on the overlay and facade elements.
It appeared and everything is growing. What to do?
It is better not to lay extruded polystyrene foam on aerated concrete. Take a picture of how the framing joint is made. I suspect it is not covered with vapor barrier...i.e. moisture from the house passes through the foam and rests on the EPS framing with all that entails.
There is mold on the eaves and gutters because of the high humidity in that area. Treat with chlorine.
Treat (if there is no frost) with an aqueous chlorine solution (bleach + water) – treat in windy weather with a garden sprayer wearing a respirator (charcoal) and safety glasses.
We have a similar story. The house is in a low-lying area, forest and river around, constant fogs.
But it's not mold, it's a type of algae, so they live on everything, including plastic. When it's alive it's green, when it's dead it's black. Cures – wiping with a rag, there is nothing left on the base at all.
No harm is done, but the aesthetics suffers.