To remove small amounts of moss from a roof, use a brush or broom to gently scrub the moss off the shingles. Cut branches that reach over the roof to help prevent the moss from reappearing.
Chlorine bleach and specialized commercial products removers also remove moss. When using chlorine bleach to kill moss, protect the surrounding vegetation by watering it thoroughly before applying a solution of TSP, chlorine bleach and water to the roof. Keep the affected areas damp for at least 15 minutes after applying the cleaning solution, and rinse with clean water.
Alternately, combine oxygen bleach, TSP and water and then apply the solution to the roof. Allow the cleaning solution to remain on the roof for at least 15 minutes, and use a broom or scrub brush to loosen the moss if necessary. Rinse the roof with clean water, and install zinc or copper strips directly below the roof ridge to effectively kill moss throughout the year.
Commercial moss prevention products are another option. Apply the moss prevention product as recommended on the product packaging.
Do not power-wash the roof to remove moss, as this may damage the shingles. If the moss damaged the shingles or underlying materials, replace the roof with shingles that contain moss-inhibiting materials.