Roof streaks and stains are commonly mistaken to be dirt, mildew, soot or mold by homeowners. However, the dark streaking and discoloration on your roof are actually caused by Algae. The streaks appear in a dark color that look like black stains running down your roof. The algae that causes this is called gloeocapsa magma which is a type of bacteria that forms when algae spores group together. Lucky for you we use the Atlas Roofing System for all of our shingle roof replacements. Our Atlas Asphalt shingles are built with Scotchgard Protector which infuses the asphalt granules with tiny ceramic algae killing copper beads. Over time, the dew carries copper ions from these tiny beads onto the roof continuously preventing algae from building up and defacing the vibrant color of your roofing. Scotchgard Protector is also the only algae-resistant roofing product for long-term protection against black streaks. When you get a roof replacement with Aspen Home Improvements we can guarantee that your roof will be protected against black streaks caused by algae for the life of the roof. Contact us for a free consultation!