( 
)What are the black streaks on my roof ?
The black stains on most roofs are a form of algae. This homeowner was told by a roofing contractor that she needed a new roof. We saved her thousands by cleaning it instead. She also informed us that others tried to remove the stains but could not!
Can They Harm My Roof?
Yes. They can grow root systems that loosen the aggregate granules that are there to help maintain the integrity of the roof surface and repel water. Some roof contractors may tell you that the black streaks you see are due to granular loss and that the asphalt is showing through. Therecently cleaned roof (above right) proves that to be false.
The dark spots created by the algae can cause hotspots on the roof which can reduce the
energy efficiency of your light colored roof. The dark algae and mosses also hold moisture on your
roof and can cause premature aging (especially during the freeze/thaw cycles in the winter)
and reduce perceived value of your home.
Moss & Lichens are the most damaging and hardest to remove. Get rid of them while they are small in size and in numbers to avoid problems later.
Warning from the ARMA
Do not pressure wash your roof. Even moderate pressure can cause damage to your roof by loosening the aggregate and causing immediate or delayed granular loss. Trust your roof to professionals that specialize in roof cleaning not pressure washing. Our process is recommended by the Asphalt Roofing Manufacturers Association who warn homeowners against using pressure washers for algae removal.
If you would like a free estimate for a low pressure, soft wash, roof cleaning please call Roof Rejuvenators of Boone toll free at 888-366-3051 or check us out online atroofrejuvenatorsdotcom
Guide created: 09/09/08 (updated 01/09/09)
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