Tag: roofing repair Telford

  • Roofing 101: Black Roof Stains

    Courtesy of BobVIla.com

    Courtesy of BobVIla.com

    Have you noticed black marks on your roof?  Chances are it's black algae.

    According to BobVila.com, "The black spots discoloring your asphalt roof are more than likely the pervasive and prevalent algae known as Gloecapsa Magma."

    This algae likes to grow in a dark moist environment, usually from dew and shade. According to the site, this algae usually starts on the north-facing sides of a roof because those sides usually receive the lease amount of light.

    And, since it travels through the air, it could've come from a neighboring home, and unfortunately, black algae thrives on calcium carbonate, which is used in most asphalt shingles.

    While the algae is not necessarily harmful (it's primarily an aesthetic issue) it can prematurely age shingles.

    DON'T use a high pressure washer to remove algae as it can harm the shingles.  It's best to gently spray the shingles with a solution of, " one cup of trisodium phosphate (available at most hardware stores), one gallon of bleach, and five gallons of water" and let it sit for 20 minutes before rinsing it off.  Be sure to apply the treatment on a cloudy day so the solution doesn't evaporate.

    While this cleans the existing algae that's there, it doesn't prevent it from coming back...

    In order to prevent algae from forming, a solution "can be created by installing copper or zinc strips under the full course of shingles at the ridge of the roof.  As rainwater washes across the metal it will create an uninhabitable environment for future spores."

    Exterior Specialties of PA is here to help with all or your roof stains, roof repair and roof installation needs.  Call us today at 215-453-9180 for your FREE estimate!