Mould or Mildew

The germination of spores contaminating offending surfaces under damp / humid conditions, generally occurs in bathrooms / sealed rooms.

Solution

Remove all signs of organic growth with a stiff bristle brush and / or washing.  Treat the area liberally with Crown Trade Fungicidal Solution .  For areas prone to condensation use Steracryl Mould Inhibiting Matt or Acrylic Eggshell.