Why are there black/green spots on my walls

Mildew is both interior and exterior problem found in damp areas receiving little or no sunlight. Mould often grows in areas where condensation forms from water vapour in the air meeting a cold surface which turns the vapour into a liquid.

What are the possible causes?

• Failure to treat existing mildew before painting.
• Failing to apply primer coat before top-coat.
• Painting over a substrate or coating from which mildew has not been removed.

How can I fix the problem?

• Treat the surface with fungicidal wash.
• Use high pressure water wash to remove loose microbes, surface contaminants etc.
• Allow the surface to dry completely before repainting..