Mildew is an unsightly fungus that appears as brown, gray and black spots on paint and other surfaces. It needs warmth, humidity and nutrients to grow—all of which are found on the interior and exterior of our homes. Poor ventilation compounds the problem. While it is impossible to guarantee that you will prevent mildew on your paint, there are some mildew-fighting strategies you can employ to keep painted surfaces mildew-free for longer
• Purchase paint that will inhibit mildew growth, particularly when painting shady and damp outdoor environments. Always use exterior paint for exterior paint projects and look for formulations containing a mildewcide. Top-of-the-line paint will be more mildew-resistant. Opt for latex paint and choose semi-gloss and gloss finishes that prevent mildew penetration. Consider painting exterior surfaces in a dark color. The dark paint will absorb sunlight and dry faster when exposed to dampness, dew or rain.
• Prime bare surfaces and apply at least two coats of paint.
• Apply exterior paint on a calm day to avoid mildew spores from blowing into your newly applied coat of paint.
• Identify and correct any sources of moisture that may be encouraging mildew growth.
• Plant trees and bushes away from painted surfaces.
• Remove any mildew you find quickly. Use a mixture of 3 parts water to 1 part household bleach. Let it stand for 20 to 30 minutes before removing with water and a rag or scrub brush.