Cleaning roof stains takes planning and caution.

 How to Clean an Asphalt Roof

Asphalt shingles provide secure, long-lasting roofing coverage. Basically care-free, asphalt roofing can be susceptible to staining from moss, mildew, algae and other moisture-related organisms. In addition to leaving unattractive dark stains, growth of moss or lichens can loosen the firm adhesion of shingle edges, creating potential areas of leakage. Both do-it-yourself experts and commercial cleaners recommend good planning and caution when taking on the job of cleaning an asphalt roof. Know the products and procedures involved to clean your roof safely.

  1. Put on protective clothing and soak shrubs or lawn close to the house or garage foundation. Keep them soaking wet during the cleaning process to dilute the impact of corrosive chemicals on plantings. Cover large established plantings with waterproof drop cloths. Soak plantings periodically throughout the cleaning process. Tie drop cloths, but remember to keep bushes wet and soak the root areas around shrubs and trees.
  1. Prepare your solution taking care to wear proper safety equipment
  1. Spray the solution over the entire surface of the roof and let it sit until stains begin to fade and become brownish. Wash the solution off the roof with your garden hose fitted with the sprayer head or remove the solution with a pressure washer. *Note that experts differ on whether using a pressure washer can loosen or peel shingles, leaving the roof vulnerable to leaks.
  1. Soak bushes, lawn and flower beds again while the roof dries. Check the fading of stains. Repeat the cleaning process if stains are still visible.
  1. Take preventive action so that algae, moss or lichens don’t regain control.
  1. Evaluate the pruning needed to improve air circulation and sunlight on your roof. Cut back branches to prevent moisture buildup, which helps reduce conditions hospitable to mildew, mold, algae and lichens.

Evaluate any pruning that’s needed to improve air circulation and sunlight on your roof. Cut back branches to help prevent moisture buildup, which reduces conditions hospitable to mildew, mold, algae and lichens.


Wet surfaces present challenges at any level, but combined with roof height, sloping surfaces, and ladders, wet surfaces can be dangerous. Cleaning a roof is heavy work; a helper may assist you in maintaining your stamina during this long job.

Custom Gutter and Roofing offers quality roof cleaning services.

Roof Cleaning is affordable and prolongs the life and appearance of your roof. Your roof is the single most valuable component of your home and it deserves to be protected from mold and fungus. Mold prevention is key to keeping your roof beautiful. Call the pros – we do all the work! (203) 648-4939