If you or your neighbors have asphalt roofing, chances are you’ve noticed dark streaks on the surface of the roof. Before you write it off as mold growth or a tree sap stain, you might be interested to know that these unsightly streaks are most likely caused by microscopic organisms called Gloeocapsa magma, a species of bacteria more commonly known as blue-green “algae”.

Roof repair company Certified Home Improvement, LLC sheds light on how blue-green algae gets on your roof as well as ways to get rid of it.

Blue-Green Algae Basics

Gloeocapsa magma is airborne and is more likely to develop on asphalt roofs. Blue-green algae does not grow on roofs with copper or zinc as these elements are toxic to the algae. The dark stains are actually due to the coating that the algae produces to protect itself against UV rays. The good news is that there hasn’t been any conclusive study suggesting that algae growth is harmful to the roofing system. Nevertheless, most homeowners prefer their roofs to be stain-free.

Getting Rid of Blue-Green Algae

More good news: you don’t need a roof replacement to get rid of algae growth. All you need is a 50/50 mixture of chlorine bleach and water. Soak the affected parts of your roof in this solution for about 20 minutes before rinsing it off. You can use your garden hose for this. If you must use a pressure washer, keep the pressure low.

Prevention

Today, there are algae-resistant shingles such as StainGuard Plus™ Shingles offered by GAF. It has time-release technology that dispenses granules of copper when the roof gets wet. The best part? These algae-resistant shingles from GAF come with a 25-year limited warranty against blue-green algae discoloration. Ask your roof contractor about StainGuard Plus™ Shingles today!

Long-Lasting, Beautiful Roofs

Certified Home Improvement, LLC is a GAF Master Elite® residential roofing contractor. We also specialize in siding installation. Call us today at (734) 522-1601 to get a free estimate. We serve Garden City, MI.