Cleaning algae roof stains:
I hate seeing black or green stains on a roof. There are many reasons that cause mold, lichen and algae to grow on a roof but that doesn’t mean you have to tolerate it. There are ways to eliminate these ugly stains and this article will show tips for cleaning roof stains and specifically algae stains off your roof.
People often ask me if these stains are a sign of roof wear. The answer to that is “no” the black staining is typically caused by algae and it will not damage the shingles, and it won’t make your roof leak. These stains usually show up on areas on the North side of a the roof or in areas that are blocked by trees or do not get much sunlight.
The black mold-like stains and streaks that appear on roofs is usually a blue-green algae (Gloeocapsa magma) These stains mostly appear on light colored roofs but do grow on all roofs.
There are all types of consumer products that you can buy to remove algae stains off roof but the best solution I’ve found is to use a mixture of two parts water to one part bleach and apply it with a garden sprayer.
For more tips on cleaning roof stains, click here.