How to Whitewash a Roof

Cover ornamental shrubs that abut the house, as well as decks or patios, with large dropcloths or old sheets. This will save you the trouble of cleaning up drips.

Sweep off debris, then power wash the roof. Mix a bleach solution, combining two cups of bleach with one gallon of water and two ounces of detergent and use this solution to clean the roof. For best results, hold the nozzle about six inches from the roof. Rinse with clean water and allow the roof to dry completely before performing any repairs.

Patch or caulk all cracks or seams and secure all flashings and roof penetrations such as chimneys. Make sure flashings are tightly secured to the roof. Add more screws or close the seam with polyester tape.

Prime the roof with a penetrating primer. Pay special attention to porous areas and cracks.

Stir the paint thoroughly or bring it to a paint store and ask for it to go in the shaker. Remember to mix it periodically as you paint.

Brush, roll or spray on the paint. Apply the first coat in one direction and subsequent coats in a perpendicular direction. Apply a generous first coat. Porous surfaces will absorb quite a bit of paint, so you may not get the exact coverage you calculated for that first coat. The second coat will require less paint than the first.

Apply on a relatively warm, sunny day, with temperatures at least 50 degrees Fahrenheit, as this will speed the drying time. A slight breeze will also speed the drying process, but strong winds will make for dangerous working conditions.

Wait eight to 12 hours before applying the next coat. Clean drips before they dry, and clean tools immediately with warm, soapy water.