Cladosporium is the most common of all molds and can enter the home in a number of ways. There are over 30 species and it is classified as "Black Mold". If you have ever seen a black pepper type substance on your toilet tank, this is likely Cladosporium. It thrives in damp, dark environments which is bad news for your attic if it lacks proper insulation. Cladosporium is an airborne allergen and can cause serious health risks.
This form of mold buildup in your attic is a direct result of water damage, as this mold, like all molds thrive in a moist environment. With proper attic insulation, you can prevent this mold from building simply by keeping your attic dry. When you do not have the right amount of insulation in your attic, warm air can rise from the home's living area and heat up the top of the roof. When this occurs during winter months, the moisture outside the roof melts and sheds to the lower half of the roof then refreezes. This is called ice damming and is responsible for moisture penetration of the roofing structure.
To prevent this mold from buildup, insulation contractors can install the recommended amount of attic insulation for your area to ensure your attic stays dry through the winter months.