DIY Doctor UK DIY Forums

Hi does anyone know what black patches on a roof timber are? They seem dry not flacky or mouldy but have spread, tomber seems solid no smell either. Near to some lead flashing. No sign off water penetration. Do I need to treat before they get worse. Any ideas thanks

You may have mould.
Mould comes in many colours.
The colour depends on what its growing on.
Buy a damp meter.