First sign of mold in this house. It is superficial since I've scraped a bit and underneath it's fine.
There is no smell and the fiberboard is unaffected. We changed the heating system 7 months ago, but on the other hand, we have installed new ventilation in the form of air supply vents in all bedrooms and living room. Exhaust is managed via a large duct fan in the basement and two Pax fans in each bathroom (running continuously). The exhaust capacity has been measured by a ventilation company. We are perceived to have very good air quality.
Previously, the rooms have been unused for 20 years as the woman before us lived on the ground floor and was hand-washed in the bathroom.
The mold is dry. No other signs of infestation than what is visible in the picture.
Why wouldn't it be on the board next to it then, as there is such a clear sharp boundary at these boards and nothing even on the edge of the adjacent boards.
Could it be that old boards have been used and that they were in a place with limewashed walls before and then reused??
Those boards must have almost looked like that when they were nailed down.
Considering that the fine boards next to them don't have a trace of the white.
If it had grown, the boards next to it should have been "infected" and the "vegetation" might have had irregular edges and not stayed within the board's edges.
