Do you know why & how fungi can damage your timber windows?
Blue Stain & Soft Rot
Blue stain is one of the so called discolouring fungi, because it forms visible, black & blue stains. The blue stain does not decay the wood itself, but it looks very unpleasant and it paves the way for other fungi that do decay wood (soft rot). They perforate the cell walls, making it easier for the wood to absorb water. Soft rot is the most dangerous form of fungi for wood. It destroys the wood