When they first notice black spots on their asphalt shingles, many homeowners assume that the discoloration is either soot from the fireplace, mildew or mold. More than likely, however, the problem is a particular type of algae called Gloecapsa Magma. Black streaks or spots will typically show up first in heavily shaded areas or on the side of the roof that faces north. Over time, however, they will spread, and even neighboring roofs can be affected.
Black Spots On My Asphalt Roof – Questions
Will the Spots Damage the Shingles?
Algae will feed on an ingredient in the shingles known as calcium carbonate. Given enough time, algae will cause premature aging of asphalt shingles, and the staining will become increasing unsightly.
Will Power-Washing Remove the Algae?
Power-washing asphalt shingles is an extremely bad idea. Asphalt shingles need their granules to retain their waterproof abilities. Many well-meaning homeowners have suffered roof leaks after having their shingles power-washed. It is virtually impossible to “fine-tune” a power washer to provide sufficient power to remove algae without also removing the granules.
Should I Hire a Roofing Contractor to Deal with Algae?
We recommend that you call a reputable, experienced contractor to handle the algae. He has the chemicals and equipment to remove the algae without damaging your roof or foundation plantings. It should be noted that the algae will probably return if steps are not taken to prevent reoccurrence. One of the best preventative measures you can take is to have your contractor install zinc or copper strips at the ridgeline and in any other locations he feels necessary. As rain runs across these strips, tiny particles of the metal wash over your shingles, creating an environment in which the spores cannot thrive. If your roof has already deteriorated beyond help, you might consider replacing them with algae-resistant styles that already have the metallic granules included.
Contact Alpha Roofing for Help
Alpha Roofing is a roofing contractor that can help you resolve all of your roof-related issues. We have been providing superior work at reasonable prices for over 35 years to residential roofing and commercial property owners in most communities in Central Texas, including the greater Austin area. We offer an extensive list of services, including moss and debris removal, re-roofs, metal roofing systems, siding installation, gutter installation and much more. We offer free quotes; simply call (512) 777-1086 or complete our handy online form.