Dirty asphalt shingle roof (left), cleaned roof (right).

If you're reading this, chances are you're trying to find roof washing suggestions because your shingles aren't looking brand new and attractive. If your roof appears dark and stained in some areas, you may assume that mold and/or mildew has established itself on top of of the shingles. However, the black streaks you're seeing are actually colonies of blue green algae. If you're seeing thick, grass-green growths on your roof instead, then you have definitely got a moss issue. The north, west, and shady areas of your roof are most at risk to these moisture-loving nuisances.

Black Streaks on Roof

Algae and moss spores are brought by the wind or animals from roof to neighboring rooftop, which is why entire neighborhoods are often impacted. Moss can seriously impact asphalt roof shingle efficiency by triggering them to curl up and blow off, ultimately causing roof leaks. Algae is also known to eat away at asphalt shingle components, particularly the limestone, developing into certain roof failure.

Additionally, getting on your roof often to clean off growth MIGHT cause damage to your roof and reduce its life expectancy by loosening the surface granules on your shingles. So, it's good to understand exactly how to clean your roof correctly to ensure that you ensure you do not need to do it too often.

Knowing this, what are the most effective methods to clean a roof of algae and moss infestation? Continue reading for our best roof-cleaning tips!

• Do not utilize a pressure washing machine, which can loosen shingles and seriously harm your roof.
  Do use a sprayer connected to a garden hose that's full of equal parts chlorine bleach and water or household  liquid chlorine bleach and water. This is the most effective method to clean a roof if you have asphalt shingles. After spraying the roof with the blend, allow it to sit on the surface for 15 to 20 minutes prior to rinsing thoroughly with clean water.



• Do not overlook your landscape and bordering areas, which can be harmed by the bleach mixture.
  Do thoroughly wet down plants and bushes  with clean water prior to covering them with plastic, after that rinse them again after utilizing the bleach solution on your roof.



• Don't assume the cleaning mixture will immediately eliminate the growth from your roof and apply the solution again.
  Have patience. The algae will eventually stream away during subsequent rainstorms, and moss will ultimately loosen up to the point where it can be eliminated with a leaf blower.



• Do not clean your roof on a bright day, which will cause the bleach solution to evaporate too fast, restricting its cleaning effects.
  Do clean your roof on an over cast, wind-less day when the wind isn't blowing and there's no danger of precipitation.



• Do not clean your roof without taking proper safety and security preventative measures.
  Do clean your roof just after establishing that you can safely get up on its surface. If the slope is too steep to quickly go across or if your house is taller than one story, you need to hire a professional roof cleaning company. If you do get up on your roof, use shoes with slip-resistant rubber soles and make certain to wear eye and skin protection.



• Don't wait until your roof is covered in algae or moss to act.
  Do trim back overhanging branches to open up the roof to sunshine, and clear particles such as sticks and leaves from its roof surface with a landscape blower if needed. You should keep gutters clean to guarantee roofs stay as dry as possible.