Causes: - Usually a combination of air pollution and dust - Coarse flat finishes are particularly vulnerable to dirt penetration - The life and beauty of exterior paints may be extended by properly washing as needed Solutions: - Wash off all loose dirt and other particles before repainting - Use a scrub brush and a detergent solution with household bleach (1 part bleach, 3 parts water) to also kill mildew if it is present - Power washing recommended for speed - Rinse to remove all loose particles |
