Roof Cleaning Q & A
Roof Stains

What are those unsightly black stains on my roof? The black stains on your roof (most commonly found growing on the north side) are a black mold fungus called Gloeocapsa Magma. These mold and algae stains are due to a limestone filler in asphalt shingles. When the roof becomes moist and does not completely dry out after a rain or dew, it adds fuel to the fire for mold and algae growth.

What are the effects of these stains to my roof? Besides the unsightly appearance of these stains, they are deteriorating and shortening the life span of the shingles. The mold and algae actually root themselves to the shingles breaking the sand granules loose, cutting the life of your roof in half. This will cost you THOUSANDS in early replacements. Long term effects on your health are possible too, because of the airborne mold spores released by these stains.

How can these stains be safely removed without damaging the roof? These stains are removed by applying a special cleaning solution using ONLY NON PRESSURE methods. Absolutely do not let any contractor claiming to use “LOW PRESSURE” or pressure wash your roof, as this will only cause further damage and void your roofs warranty. Even low pressure is too much. We use non pressure to apply the cleaning solution recommended by ARMA (Asphalt Roofing Manufactures Association) and GAF (largest producer of asphalt shingles). The majority of the time this solution is applied from the gutter line. This allows workers to stay off the roof, saving it from more granule loss. Once the solution is applied, it dwells on the roof allowing it to safely kill and remove any growing mold, mildew, and algae. A good rain will safely and effectively remove and rinse any dead mold and algae from the roof. The solution loses it’s effectiveness after 6 hours do to heat and UV light.

Does this process affect my plants and animals? No. First, all downspouts are bagged to collect what little, if any, run off solution from the roof. This keeps any solution from running into the ground, retention ponds, or storm drains. The used solution is then taken off site and disposed of properly at the correct waste water treatment facility. Second, all plants and landscape are watered, and then covered. Watering of plants and landscape is continued throughout and after the cleaning process. This usually leaves customers with more lush plants and flowers after the roof cleaning.

How much does a roof cleaning typically cost? The average cleaning of a roof cost between 5% and 15% of what it would cost to replace it. The majority of the time this saves the customer an amazing 90% on having to replace the roof, when it really just needs a good cleaning in the first place.


Prestige Pressure Washing & Roof Cleaning offers a Customer Satisfaction and  3 YEAR Roof Stain Guarantee! We also offer a Limited Lifetime Warranty on the shingles with our Preventive Maintenance Plans. Don’t let those stains ruin your roof any longer; call the “Exterior Restoration Specialist” for your FREE Estimate and Demonstration!

          Prestige is a fully insured, certified, member of the BBB roof cleaning company. We also carry Workman’s Comp insurance.