By Angie Hicks
What causes those dark marks, and what can be done to eradicate them?
Roof experts who are highly rated by members of Angie’s List say the source is an algae called Gloeocapsa magma. And depending on the age and condition of your roof, cleaning may be the most cost-effective solution, since it’s about 5 to 10 percent of the price of a roof replacement, which can be as much as $10,000.
Algae-caused marking isn’t preventable but can be removed, though not always permanently. The algae survive through photosynthesis and by feeding on limestone filler used in asphalt shingles.
Black marks became a problem about 20 years ago, when manufacturers began adding limestone granules to add weight to material used to coat shingles.
Copyright© 2016 RISMedia, The Leader in Real Estate Information Systems and Real Estate News. All Rights Reserved. This material may not be republished without permission from RISMedia.
Content on this website is copyrighted and may not be redistributed without express written permission from RISMedia. Access to RISMedia archives and thousands of articles like this, as well as consumer real estate videos, are available through RISMedia's REsource Licensed Content Solutions. Offering the industry’s most comprehensive and affordable content packages. Click here to learn more! http://resource.rismedia.com