How to Dissolve and Remove Roof Mildew
- 1). Power wash the roof first to see if the mildew comes off without any chemical treatments. When power washing the roof, always aim the hose downward from the top of the roof toward the eaves to prevent water from getting up under the shingles. You do not necessarily have to rent a power washer, though they do provide the highest pressure. Try the highest setting on your garden hose first.
- 2). Scrape a small area of mildew off of the roof with a cleaning brush, or even a toothbrush, if the areas are very small. Brush downward toward the eaves to prevent wear and tear on the shingles.
- 3). Use a chemical cleaner if the mildew does not come off with water or brushing alone. Products created for cleaning mildew and algae from roofs include "Moss Out," "Spray" and "Forget." A more natural alternative to these products, according to the Ask the Builder and Danny Lipford websites, is oxygen bleach. To use oxygen bleach, mix the powdered bleach with the amount of water indicated on the packaging, put it into a spray bottle and spray it onto the roof on a cloudy day. Use a brush to scrub the mildewed areas gently and then rinse the entire roof down with a garden hose.
