Mildew: Areas of black, gray, brown spots formed on paint and other surfaces, particularly in damp, shady areas.
Mildew probable causes: Warm, humid conditions, poor air circulation and little direct sunlight, like under eaves and overhangs. Shrubbery planted too close to a building is an ideal place for mildew to grow. Mildew must be removed before painting or it will come through the new paint.
Mildew solutions: Remove all mildew by scrubbing with a solution of household bleach and water. Mix 1 part bleach to 3 parts water. Wear rubber gloves and eye protection. Power washing is recommended for larger areas. Rinse thoroughly with a garden hose.
Primers & exterior finishes: Priming is essential for better adhesion, sheen uniformity, mildew control and durability. Select a top quality exterior paint in the color and sheen of your choice containing mildewcidal protection.