Mould is the black, grey or brown spots that can appear on the painted surface.
- Mould forms most often on areas that tend to be damp, or receive little or no direct sunlight (e.g. bathrooms, kitchens and laundry rooms)
- Use of flat or matt paints in areas subject to moisture
- Use of low quality latex paint
- Failure to prime a bare wood surface before applying the paint
- Painting over a substrate or coating on which mildew has not been fully removed
Test for mildew by applying a few drops of household bleach to the area; if it is bleached away, the discolouration is probably mildew. Remove all mildew from the surface by scrubbing with a diluted household bleach solution (one part bleach, three parts water), while wearing rubber gloves and eye protection. Rinse thoroughly.
To protect against mildew, use a premium quality water-based paint, and clean when necessary with bleach/detergent solution. Consider installing an exhaust fan in high moisture areas.
If the area is subject to frequent moisture, e.g. bathrooms, consider using Wash&Wear® +Plus Kitchen & Bathroom.
More problem solving advice
Have you noticed small droplets appearing on your fresh coat of acrylic paint? Don't panic – it’s a normal part of the curing process. Find out more.