subject: Attack Of The Killer Roof Algae! [print this page] While those black streaks on your roof are no immediate danger to you or your family, they are growingand could be reducing the lifespan of your shingle roof. No, those streaks aren't dirt, fungus, or mildewthey're caused by a particularly nasty bacteria called Gloeocapsa Magma.
Gloeocapsa Magma runs rampant in places where there is a significant amount of humidity. Unfortunately, this includes roughly 80% of homes in the United States. Gloeocapsa Magma actually feeds on limestone, which is used as a filler material in the asphalt found in most of today's shingles. Substantial growth of this bacteria has been shown to reduce the life of your shingles, in addition to giving your roof a prematurely aged or damaged appearance. If neglected, the bacteria will continue to grow and could eventually damage the shingles.
If your roof is beyond a simple cleaning, however, consider having 'algae resistant' asphalt shingles installed. Today's premier roofing contractors offer shingle products who's color granules are infused with copper making the shingles 'algae resistant'. (Don't worry, you can't actually see the copper in the shingle.) Copper has been shown to minimize the Gloeocapsa Magma's ability to feed on the limestone in your shingles. Examples of algae resitant shingles include Art-Loc (a diamond shaped interlocking shingle) and Stormmaster LM (an architectural shingle). Shingles such as these can help to keep your new roof looking new.
While algae resistant shingles come at a slightly higher price point, they should provide long-term savings in the form of reduced roof maintenance and keep that killer algae at bay.
