Roof Streaking and Algae Explained
ROOF CARE GUIDE
Fisher Construction LLC has been a licensed roofing contractor serving Moline, IL, and the surrounding Quad Cities region since 2018. Black streaks and algae on a roof are caused by Gloeocapsa magma algae, a bacteria that spreads through humid air and settles on shaded, moisture-prone shingles. Humidity and shade are the two biggest drivers of growth.
WHY IT HAPPENS HERE
Humid Summers Feed Algae Growth on Quad Cities Roofs.
Midwest summers bring heavy humidity and morning dew that keep shingles damp longer than they should be. Shaded, north-facing roof slopes stay wet the longest, giving algae spores a place to settle and spread. Older roofs with more granule loss lose their protective coating, so algae takes hold even faster on these surfaces.
Streaking Signals More Than a Cosmetic Problem.
Dark streaks are not just an eyesore. They trap moisture against the shingle surface, which can shorten the roof's lifespan over time. Streaking also hurts curb appeal and resale value. Pressure washing on your own often strips granules and causes more damage than the algae itself.
WHAT WE LOOK FOR
A Professional Inspection Confirms Algae Versus Roof Damage.
Our inspection tells surface algae apart from real shingle deterioration. We check for granule loss and look at the overall condition of your asphalt shingle roof to confirm whether cleaning or replacement is the right next step.
GET STARTED
Get a Free Roof Assessment Today.
A professional look at algae or staining costs nothing and helps you decide between cleaning and replacement. We're available Monday through Saturday, 8 a.m. to 8 p.m.
