Black Rooftop Stains

There are many things that may mar the appearance of an otherwise attractive roof’s surface. One of the most common and frustrating issues that homeowners deal with is the appearance of black roof stains. Black stains are used as a catch-all term to describe all types of other stains, including brown, green, red and grey. Ocean County Roofing strongly recommends getting a professional to look at the roof if the homeowner is not sure about certain types of staining.

Extractive bleeding is one of the most common causes behind black stains along the rooftop’s surface. These stains are sometimes mistaken for black algae or black fungus, but they will typically only occur on asphalt shingles. They are caused by a loss of black pigmentation in the shingles’ mix. These stains will usually leave black streaks that run down the roof, and are an indicator of a low-quality roofing product. Sometimes this type of staining can be particularly problematic for homeowners because of the implications of defective materials.

Another common cause behind black staining is black algae.

This is usually the most probable cause behind staining because of how this type of algae can grow on many different types of roofing materials, without being solely limited to asphalt products. This type of staining appears in the form of black patches and discoloration, commonly appearing in areas where the roof is shaded, whether by nearby trees or debris. It is not the same thing as a fungal growth, though it may be treated with similar products.

If the roof has a chimney, it may be an explanation for another type of black staining. Sometimes the soot and smoke that rises from the roof will drift towards the shingles, resulting in black soot staining. This type of staining is characterized by its proximity to the chimney itself, making it much easier to identify. These stains will appear in line with the chimney and are usually not far from it. If the homeowner has a chimney and the staining is farther away from it, then soot may not be the cause.

No matter the reasons, it is important for these stains to be addressed as soon as possible to ensure a more uniform appearance across the roof. In the case of black algae, if the stains are left alone for too long, they may cause structural damage to the shingles, which can increase the potential for damage to the roof itself. Any of the roofing contractor from Fortified Roofing of Ocean County can answer your questions about skylights or new roofs.

Common roofing term explained by the contractors from Fortified Roofing of Ocean County:


Algae refers to a very diverse group of tiny organisms that frequently grow in large clusters along a surface. Most lack the distinct cellular types that are typically found in common plants, and there are many different types, usually distinguished by their color.

Question and answer courtesy of the Ocean County roofing contractors from Fortified Roofing:

Is it possible to get rid of the staining outside of a professional service?

While it is possible to purchase the necessary products to perform the cleanup, it is generally not recommended for most homeowners because of the associated safety risks. Trained specialists will be able to take the necessary precautions when they perform the cleaning, guaranteeing bodily and property safety.

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