Dark spots that may appear over time on shingled roofs are the result of several factors, including:
Growth of algae and lichens
In most cases, the spots that appear on the surface of the shingles are caused by deposits of algae and lichens and can be green, gray, blue or black. In the first phase, they appear in the form of points that later develop gradually, turning into spots, which eventually extend over larger areas.
In the vast majority of situations, velvety masses of moss develop on the surface of the roof with northern exposure. Unlike algae or lichens, moss can cause a lot of problems in addition to aesthetics. Its roots tend to penetrate under the covers, raising or deforming the shingles, affecting the overall capacity of the roof to withstand winds, with a major risk of infiltration during storms or in the cold season.
Fortunately, algae, lichen or moss deposits can be removed relatively easily from shingled roofs. Specialty stores sell a wide variety of liquid biocide solutions designed to remove these deposits and clean the stained shingles.
If you are not sure about doing the cleaning process yourself, the best thing is to call the Fort Smith roofing contractor specialists, because this way you`ll get warranties that the work has been done efficiently and safely for your roof and the vegetation around your house.