First was the existing siding with strong detergent and water. If there is mildew then mix one cup of clorox bleach per one quart of water. Wash and rinse thoroughly.

Paint the siding with 100 percent acrylic latex house paint. Make sure you go directly to the proprietary paint store (ex. Sherman Williams). Some department and hardware stores sell watered-down discount paints even though it is the same manufacturer. They do this to remain competative.