How to Remove Moss From an Asphalt Roof

Moss tends to grow on asphalt roofs in damp, humid climates. North-facing roof portions surrounded by overhanging trees and vegetation attract moss due to retaining moisture and inadequate sunlight. Moss roots penetrate asphalt shingles until they eventually deteriorate and become irreparable. Accumulated moss can create dams and obstruct water drainage, causing roofs to develop leaks. Promptly treat moss to protect the roof's structural integrity and improve the home's appearance. Remove moss from an asphalt roof using basic solutions and supplies.

Inspect asphalt shingles for moss annually.
  1. Spray the shrubs, plants and grass underneath the roof eaves with water from a garden hose. Cover the vegetation with plastic drop cloths to protect them from bleach runoff.

  2. Put on protective clothing, slip-resistant shoes, safety glasses and rubber gloves for protection.

  3. Mix 1 gallon of water with 1 gallon of chlorine bleach in a plastic bucket. Pour the bleach solution into a clean pump sprayer.

  4. Brush the excess moss down the roof using a telescoping pole brush. Remove as much moss as possible.

  5. Spray the bleach solution liberally over the mossy shingles. Keep the solution on the roof for 30 minutes to thoroughly kill the moss.

  6. Scrub the shingles with the telescoping pole brush to remove the remaining dead moss. Brush down the shingles to prevent damaging them.

  7. Rinse the shingles with water from the garden hose to wash away the bleach solution. Spray down the shingles to prevent water from becoming trapped underneath them.

  8. Allow the shingles to air dry.


  • Do not use a pressure washer on the asphalt shingles; the powerful jets can break the shingles.
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