To remove it you can try wet forget no scrub outdoor cleaner.
Roof algae cleaning solution.
Put in a spray bottle to apply to small patches.
We now offer exterior disinfection sanitization to combat the spread of covid 19.
Apply with a sprayer and allow the solution to dwell on the roof surface for 15 to 20 minutes and then rinse thoroughly with low pressure water.
Our low pressure methods are safe on your roof and siding and we deliver same day results.
If not prevented it will take over the maximum portion of your house.
A homemade cleaning solution can be mixed using a quart of chlorine bleach and a gallon of water with one fourth of a cup of trisodium phosphate stirred in.
They re likely to damage the shingles just be sure to wet your foundation plantings first and rinse everything in clean water when you re done.
No pressure washers please.
The most effective method of cleaning algae and moss from a roof is with a 50 50 mix of laundry strength liquid chlorine bleach and water.
Wet forget no scrub outdoor cleaner.
The second method is to spray on a coating of stain blocking solution defy stain blocker for roofs is one product but there are other brands as well a stain blocking product can buy you up to three years of protection from algae.
The less expensive solution is to spray wash the roof with a 50 percent mix of water and bleach to get rid of the algae.
Life is dirty clean easy.