Black Streaks on Roof and Green Stuff on Siding
Black Streaks on Roof and Green Growth on Siding
Black Streaks on Your Roof
Let’s begin with the black streaks on your roof. These unsightly marks are caused by layers of microorganisms. In the early years after your roof is installed, you may not notice anything unusual. However, between 4 and 7 years, black streaks often begin to appear, usually on the north-facing side of your roof. By 7 to 12 years, these streaks may spread across the entire roof.
The good news? These streaks can be professionally removed by a roof cleaning service, like Outdoor ProWash LLC in Nashville, TN. And no, black streaks don’t necessarily mean your shingles need replacing—although after 12 to 15 years, it might be worth considering.
These microorganisms trap moisture, creating a favorable environment for other organisms to thrive. Over time, this growth forms root-like structures that can penetrate the shingles, loosening granules. While this may slightly reduce the lifespan of your roof, most homeowners are more concerned with the unsightly appearance of the streaks. If you’re reading this, you probably just want them gone!
What Causes Black Streaks on Roofs?
The combination of heat, moisture, and nutrients creates the perfect breeding ground for these microorganisms. In some cases, these organisms even feed on the materials in your roofing.
Green Growth on Siding
If you live in the South, you’ve likely seen the green growth on siding—or perhaps on your own home. This growth can spread across fascia, trim, vinyl windows, and even gutters, where it may appear black or spotted. It’s especially noticeable on the front of gutters and in shaded areas.
This “green stuff” is a mix of microorganisms that thrive on nearly any surface. Vinyl siding is particularly vulnerable during certain seasons when dew forms like condensation on a cold glass. This moisture, combined with dust on the surface, creates the perfect conditions for airborne spores to grow.
While brick siding is less prone to this growth, it can still occur in areas exposed to constant moisture, such as near overflowing gutters, damp ground-level areas, or horizontal surfaces where water collects.
What Causes Green Growth on Siding?
The same combination of heat, moisture, and nutrients encourages green growth. In this case, the “nutrition” often comes from dirt, hydrocarbons, or even aging paint. Over time, the biocides in paint wear off, and some of its components can even become a food source.
This green growth—often referred to as mildew—commonly forms near dryer vents or on the north side of houses, where conditions are ideal for its spread.
Want to Get Rid of It?
Professional cleaning services can effectively remove black streaks from your roof and green growth from your siding, restoring your home’s curb appeal. Visit our Roof Cleaning in Nashville, TN page to learn more about our services and how we can help!