What is the Black stuff on my roof and why do I need to clean it?

Featured image for post: What is the Black stuff on my roof and why do I need to clean it?

The Florida sun is great! Tourists spend vacation time here and some part-time residents choose to live here during the year. But, as you know living in Southwest Florida, the sun can be very harsh on your home and property. The heat and high levels of humidity create the perfect habitat for the growth of mold, fungus, algae, or mildew.

That black stuff on your roof is Gloeocapsa Magma

Gloeocapsa Magma is a type of algae that thrives in humid and warm climates. It usually appears first on the North Slope of the roof or home where shade is prevalent, and moisture tends to accumulate. The result is usually black-streaked areas. The algae produce a dark-pigmented sheath to protect it from ultraviolet rays. By the time the black streaks are noticeable, the algae usually have been growing for months or years – the result of generations of dead algae cells built up over time.

Once attached algae feed on the dead organic matter and accumulate dirt. This causes the surfaces to deteriorate prematurely and diminishes the roof’s ability to reflect heat rays. If not treated, cleaned, and rinsed away, algae will
reduce the life of your roof, paint, and other surfaces diminishing your home’s curb appeal and increasing your home cooling expenses.

Debris and Organic Material causes Gloeocapsa Magma to grow

Organisms grow and thrive on the dirt, debris, and dead matter used in the manufacturing process of your roof, pool cage, or even concrete decking. And after a hurricane, there is so much cleanup and building/repair work that there is a ton of organic matter and debris left behind. The aftereffects of these organisms wreak havoc on these surface structures outside your home. The elements weaken the structure and can cause hundreds of dollars in repairs and when left untreated can cause more maintenance than necessary here in Southwest Florida. This is why it’s extremely important to clean not only your roof but your entire home regularly.


The sight of algae, fungus, and black dirt is not appealing to anyone. If the surface of your lanai deck, driveway, roof, or any other outdoor space has this type of growth, it’s truly time for professional cleaning. Luckily there are easy ways to prevent and treat these issues in Sarasota, Charlotte, Manatee, and Lee Counties through the professional services offered by Hoover Pressure Cleaning. Give us a call today and we will wash all of your ick away!!

From the roof to the street, with Hoover your cleaning is complete.
We proudly serve Charlotte, Sarasota, Lee, and Manatee Counties.

If you would like a free estimate simply fill out the contact us form or call 941-687-6886 today.