Black streaks on your roof may indicate that it either has mold or algae. One of the two is more harmful to the roof and more difficult to remove.

In this post, one of the most trusted roofers, Roofing by Curry differentiates mold from algae.
Algae vs. Mold
Algae is a moss-like plant that spreads in neighborhoods through airborne spores. They are more prevalent in humid climates and is a common issue in asphalt roofs. Though it doesn’t cause any damage to the roof and to your family’s health, it can significantly reduce your home’s curb appeal.
Mold is not that common in roofs, but severe mold growth can cause health problems in the household including asthma, eye irritation, headaches, and lung problems. They usually grow in damp, warm, and poorly ventilated areas like attics and basements. From there, it can spread to your roof, siding, and deck.
It’s more likely that your roof only has algae if you didn’t find any mold indoors. It’s important to inspect humid areas of your home to make sure that there’s no mold growth.
Prevent Algae and Mold
Regularly wash your roof to prevent these algae and mold growth. Hire professional roofers to make sure that the area is thoroughly cleaned. Aside from having the right equipment, they are trained to perform roof inspections.
Many homeowners make the mistake of using too much pressure when washing the roof. This can damage your roof and cause injuries. Keep in mind that too much pressure only makes the surface wet but it doesn’t do a good job in removing stains.
Choose one of the most trusted local roofers, Roofing by Curry for professional roofing services. We also offer high-quality shingle, tile, and metal roofing. Call us at (941)-270-4770 or fill out our online form for a free estimate. We work with homeowners in Sarasota, FL.