Does your roof have mysterious black streaks on it? Perhaps you took one look at those black streaks and immediately began calculating the cost of an overhaul. Or perhaps you didn’t notice them until after you already put your home on the market. There’s nothing more frustrating as a homeowner than seeing your home deteriorating and not knowing why.
Thankfully, there’s an explanation for those ugly black streaks. Those black streaks are, most likely, blue-green algae. Consider it a bi-product of the Alabama warmth and humidity!
How to get rid of the blue-green algae on your roof

A gentle pressure/soft wash will do the trick.
Now before you head over to Amazon to buy a pressure washer, understand that we do not recommend DIY-ing algae removal. The goal is to remove the algae without damaging your shingles, and an experienced pressure washing service is going to be able to do that best. Plus, a pressure washing professional can educate you on how to prevent the algae from coming back.
Is it always algae though?
While algae is the most common cause of black streaks on your roof, there are some cases where dirt or mold is to blame. Self-diagnosis may seem like the cheapest option, but mold can cause serious damage to your home and is often a sign there are other problems such as leaks in your roof. So if you’re not able to pinpoint the issue, it’s best to get a second opinion. (Hint: your pressure washing service should be able to do that for you too!)