• 70% water, 30% white vinegar makes a great all-purpose cleanser that removes light mold and mildew stains.

• For a stronger solution, mix together one-third cup powdered laundry detergent, two-thirds cup powdered household cleaner, one quart liquid laundry bleach and one gallon of water.

• If you are concerned about landscaping, use a solution comprised of one gallon of water mixed with one cup oxygen bleach in a bucket. The oxygen bleach will clean the vinyl without damaging your landscaping.

• Simple Green offers an environmentally friendly cleaner that is specially formulated for use on vinyl and aluminum siding, stucco, terra cotta roof tiles and painted wood. The non-toxic biodegradable concentrate can be used manually or with pressure washers.

• General household cleansers (e.g., Fantastik, Murphy’s Oil Soap, Windex and Lysol) can be used on tough dirt and stains, including those created by top soil, grass, grease, oil, rust, crayon, ink and bubble gum. Rust stains may be removed using products designed for this purpose (e.g., Super Iron Out and Instant Rust Out).

Source: http://www.bobvila.com/articles/roof-leaking-repair/#.U45cRCiiX94