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How To Clean A Shingle Roof The Right Way

Updated: Sep 18, 2020

Roof Cleaning The Right Way


Roof Cleaning can be done by a homeowner but having the knowledge and proper equipment to safely and effectively clean it is better left to a professional roof cleaning company. We will walk you through what we feel is the best practice for safely cleaning your roof while protecting your property from other damage.



What Causes The Ugly Black Streaks On My Roof?


Gloeocapsa Magma - The black streaks running down your asphalt shingle roof are actually a spore based algae named Gloeocapsa magma. As the algae grows and spreads, it develops a dark, hardened outer coating, which results in the black stains you see. The algae actually feeds on the limestone in the shingles, not only making your roof look ugly but prematurely deteriorating the shingles.

Is It Safe To Clean My Roof Shingles?


It is very safe when done properly. Most professional exterior cleaning companies have low pressure, soft wash systems that safely clean the shingles and follow the methods endorsed by The Asphalt Roofing Manufacturers Association safely clean your roof.


Roof Cleaning - A Step By Step Guide?


  • The first thing to do is assemble the needed supplies, the applicator, the chemicals and surfactants and of course your ladder and a garden hose. Before you begin, it’s important to check for any damage and repair if needed.

  • Clean out your gutters and downspouts. You’ll need the cleaning solution to drain off the roof during rinsing.

  • Protect your property. Move any furniture, potted plants, etc. away from the house. If you’re using a bleach solution cover any delicate plants. Rinse down your lawn and plants before you begin deep cleaning so the water dilutes harmful bleach. It is VERY important to continue to rinse your plants during and after as well.

  • Remove debris from the roof. Before you clean stains, you’ll have to climb up onto the roof and take off twigs, leaves, and anything else that would get in the way. Pick them up with your hand, use an air blower, or gently sweep them off with a broom

Mix your cleaning solution. You can mix your own solution using a quart of standard laundry bleach and a gallon of water. Optionally, add ¼ cup of a non-ammonia heavy cleaner such as TSP (trisodium phosphate) for extra cleaning power and a 1/2 of Dawn Dish Detergent for added "cling".

  • Bleach is caustic to the roof and plants. At most, the bleach should be 50% of the solution.

  • Spray your cleaning solution. Load the solution into a sprayer. Using slow, even strokes, coat the shingles. Make sure you don’t miss any spots, or else your roof will come out spotted. Leave the solution on.

  • Reapply the solution to any areas that need to be retreated. Light stains left at this point will wash off over time as long as rain and sunlight can reach the areas.

Dirty Roof With Black Streaks - Before Soft Washing

Clean Roof With No Black Streaks - After Soft Washing


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