Cause The appearance of mildew depends on various conditions, which are: continuously high humidity (as the humidity increases, mildew growth becomes more rapid) , high average temperature (optimum temperature for mildew growth is 77°F), poor ventilation (still air increases mildew growth), composition of surface (mildew will grow on any surface that provides a nutrient, even dirt), light colors of paint film (colors that do not absorb the sun's heat provide a surface for mildew growth, while dark colors become hot and discourage mildew growth).
Solution
Wash mildewed areas with a solution of one part household bleach and three parts water. This will destroy mildew and bleach stains caused by mildew growth. Apply solution by brush or a garden sprayer apparatus. Heavy mildew may require additional applications, and scrubbing may be required. Flush area with clean water to remove bleach solution. Allow to dry thoroughly.
