Roof algae thrives in humid and warm climates and usually appears first on the North slope of the roof where shade is prevalent and moisture tends to accumulate. The result is usually a black streaked roof. Roof algae and moss spores are carried by the wind until all roofs in the area are infested. Roof moss is very dangerous because it will grow underneath the roof shingle and act like a sponge soaking up water after a good rain. Eventually the moss will cause roof leaks if not treated. Roof moss also accumulates on the North side of the home or where shade is most prevalent. Contact us for more information on maintaining and treating your roof.