What is that green fuzzy stuff on my shingles? It could be what is called Moss. If you live in a damp warm area, that has alot of tree's and vegetation, you could develop moss. If your home face's the north you could also be susceptible to moss, this is due to the lack of getting sunlight. Therefore, your home retains moisture.
Shingles with moss are more likely to have aesthetic problems, and then you get damage to your home. Moss will obstruct water flow from your roof as well as drainage. It will create dams and then will cause leaks. If you leave the moss on your roof, the roots can then penetrate your shingles and then you will have permanent damage. It is imperative to kill the moss on your shingles to preserve the structure of your home.
Following some simple steps can kill the moss problem on your roof. First you want to spray some water from your hose onto all your vegetation that is around the perimeter of your home. Next cover it with plastic sheets for added protection from any chemicals that are going to run off your roof. Protect yourself with the right clothing, rubber gloves and most important safety glasses. Make sure you also are wearing slip resistant shoes.
Now it is time to mix one gallon of chlorine bleach with one gallon of water in a bucket. Then pour this mixture into a clean pump sprayer. You want to spray your bleach solution on the mossy shingles. This mixture will stay on for thirty minutes, making sure the bleach kills the moss. After thirty minutes you want to scrub the shingles with a nylon brush and get the moss removed. Brushing downward will help protect your shingles from damage.
The last step is to rinse. Just use your garden hose once again to rinse all the bleach mixture from your roof. This is also done in a downward direction. Doing it this way will help prevent water getting trapped underneath your shingles, and allow your shingles to air dry properly.