The Cause of Roof Stains
The ugly, dark stains that are so prevalent are caused by a very hardy “blue-green” alga, Gloeocapsa magma, which thrives on the asphalt shingled roofs in much of the country, especially in the more humid areas. Growth normally starts on the north side as well as shaded areas of the roof. As the algae grow, it holds moisture allowing the growth to accelerate. Thus the roof stains get worse and worse over time.
Algae spores are carried by wind, birds, squirrels, etc. Years ago, stains on asphalt shingled roofs were not a significant problem. Today it is a big problem because the design of asphalt shingles has changed over time. For the last 30 years or so, asphalt shingles have been manufactured using limestone as the base filler. Unfortunately, limestone is a favorite food of this strain of algae. The algae used to starve to death when it landed on your roof - now it thrives on your roof.
There are other types of stains found on roofs. Green roof stains are often caused by mold and mildew. Lichen & moss also cause stains B&B also removes and prevents stains caused by all these organisms.
Algae also Damages the Roof & Shortens Roof Life
It is bad enough that algae causes’ ugly roof stains, unfortunately it also damages the roof. The algae takes root on the shingles dislodging the granules which protect & color the roof. It holds water to the roof's surface and can cause decay & rot of the roof's underlayment. Not only is your roof being discolored by the algae, but it is shortening the life of the roof leading to earlier than necessary roof replacement.
There are Three Ways to have a Clean Roof Again
1.
Re-roof - an expensive option. Your roof likely has more useful life.
2.
Power Wash or Brush Clean - damages the roof shingles by breaking away the granules that protect & color the roof shortening the life of the roof.
3.
Get B&B Roof and Fence Restoring to RENEW your roof.
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