Have you noticed dark streaks or green patches on your roof? While they may seem like a cosmetic issue, moss and algae can affect your roof's performance if left untreated. Understanding the difference between the two—and knowing when to take action—can help extend the life of your roof and protect your home. What's the Difference Between Moss and Algae? Algae typically appear as dark streaks running down your roof. They're common in humid areas and tend to grow where moistur