Brightly colored "cool" roofs reflect sunlight, lowering the temperature in the home and helping to conserve energy. The move toward energy-efficient roofing has driven many homeowners to seek out ways to brighten up traditional asphalt roof shingles, which typically comes in shades of gray or black. While many manufacturers provide paints and coatings designed for asphalt roofing, homeowners should thoroughly weigh the potential risks and benefits before painting asphalt shingles.
Manufacturers' claims relating to asphalt roof coatings range from protection against mold and mildew to greater reflectivity and longer lifespan. The American Society of Home Inspectors cautions homeowners that the effects of field painting shingles have not been well documented, and this process is likely to have negligible effects. Consumers should thoroughly research products before applying them to shingles. In some cases, painting shingles can actually harm the roof by increasing the risk for water damage and lowering vapor permeability. Always check local building codes before painting or coating your roof.
If you choose to paint your roof, contact the shingle manufacturer first to see how doing so could affect your roof and warranty. Choose a product designed for asphalt roofs, and follow all applications instructions carefully. Apply these products with a roller or sprayer only to clean, dry roofs after removing mold, mildew and other contaminants. Keep in mind that these products are typically not designed to extend the life of your roof or repairs leaks or damage.