Why Your Bluffton Roof Has Black Streaks (and How to Remove Them Safely)

If your roof in Bluffton, Hilton Head, or anywhere in Beaufort County has dark streaks running down it, you’re not looking at dirt or age. Those black streaks are a living organism, and left alone they will spread and shorten the life of your roof.

The stains are caused by a blue-green algae called Gloeocapsa magma. It feeds on the limestone filler in asphalt shingles and thrives in exactly the kind of warm, humid, coastal air we have year-round in the Lowcountry. That’s why roofs here streak faster than roofs in drier climates. The algae holds moisture against your shingles and reflects less heat, so beyond the ugly look it can actually raise your cooling costs and cause shingles to deteriorate early.

Here is the most important thing to know: you should never pressure wash an asphalt shingle roof to remove these streaks. High pressure strips away the protective granules and voids most shingle warranties. The correct method is soft washing, a low-pressure application of a specialized cleaning solution that kills the algae at the root and rinses clean. Done properly, a soft wash removes the black streaks completely and keeps them gone far longer than blasting ever could.

At Bluffton Soft Wash Company we soft wash roofs across Bluffton, Hilton Head Island, Okatie, Sun City, Palmetto Bluff, and Beaufort. We use the safe, manufacturer-approved low-pressure method that protects your shingles and your warranty while restoring your roof to a clean, uniform color.

If you’re seeing black streaks, don’t wait for them to spread. Call us at (843) 422-2331 for a free roof evaluation and quote.