How to Clean a Roof With Chlorine Bleach

Keeping roofs properly maintained is essential to their aesthetic appeal and longevity. Exposure to air-borne algae spores, mildew and dirt causes roofs to develop dark streaks and stains. Moss can grow on north-facing sides of roofs and areas with high moisture or humidity. Untreated moss on roofs can cause water drainage problems and eventually permanent damages to roofing materials. Although algae cannot structurally harm roofing materials, the stains are visibly unappealing. Cleaning roofs with chlorine bleach removes algae, moss and dirt to restore roofing materials.

• 1

  Don protective clothing, such as a long-sleeve shirt, pants and slip-resistant shoes, as well as work gloves and safety glasses to prevent the bleach solution from burning your skin.

• 2

  Attach a spray nozzle to a garden hose. Spray the grass, plants and bushes around the perimeter of the house with water from the garden hose to prevent bleach runoff from killing the vegetation. Cover the vegetation with plastic tarps.

• 3

  Fill a pump garden sprayer with 1 gallon of cold water and 1 gallon of chlorine bleach. Thoroughly mix the solution with a paint stir stick.

• 4

  Spray the bleach solution liberally onto the roof. Stand on a sturdy ladder or the roof to access the affected shingles. Allow the solution to soak into the roof for 15 to 30 minutes.

• 5

  Brush down the shingles with a pole brush to remove algae stains, moss or dirt. Do not brush against the shingles to prevent damaging them.

• 6

  Spray water from the garden hose down the shingles to rinse off the loose debris. Do not spray water up the shingles. Thoroughly rinse the roof to ensure all moss, algae and stains are completely removed.

• 7

  Allow the roof to air-dry. Repeat the cleaning process if necessary.