At one time it was quite rare to find black algae on NH roofing, but over the past few years warmer temperatures and high moisture levels have caused algae growth to become more widespread in the New England region. The ugly black streaks algae leaves behind on a roof’s surface hugely detract from a home’s curb appeal.

Black algae spreads by wind from place to place, much like dandelion seeds. When algae spores land on a “friendly” roof – one that’s covered with asphalt shingles containing crushed limestone, an excellent food source – they begin actively growing. As cells grow, die and then decay, unsightly dark stains are left behind. This process causes no actual damage to your shingles, but might leave you wondering if something’s wrong with your roof! Never fear … the algae-resistant shingle is here.

The concept behind algae-resistant shingles is quite simple. Copper or zinc, one of the main ingredients in this type of shingle, poisons algae so it’s unable to survive on the roof surface. The metals present in algae-resistant shingles are further activated by rain, which distributes the poison along the roof’s surface.

Many of today’s top shingle manufacturers, including GAF, offer algae-resistant shingles in a variety of colors to compliment your home. These shingles do cost a bit extra, but are well worth the money if you find algae staining bothersome and you don’t want to pay for frequent cleanings. For more information about algae-resistant shingles and to schedule a FREE roofing estimate, call AJC Roofing today at (877) 578-0494.

Mark Freeman has written 106 articles on this blog.

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