Spring is here at last! When you step back and ponder your summer projects, look at your roof.
- Does your roof look dirty?
- Have black streaks?
- Is there moss appearing?
Unsightly black stains or streaks on asphalt shingles are caused by a hearty form of airborne algae called Gloeocapsa Magma. The algae feeds on the crushed limestone that is used in asphalt shingles. Rain spreads the algae down the roof, causing the black streaks. Shade and moisture encourage this growth, usually on a north-facing or shaded part of a roof. This is why you may only notice it on parts of the roof.
These streaks are not only unsightly, ruining the curb appeal of your home, but can cause the shingles to fail prematurely. The algae and moss cause the shingles to absorb heat, which is one of the major causes of shingle failure. Also the roots tend to grow up under the leading edge of the shingles where it stays moist the longest. These roots can actually break the seal of the shingle leaving it more suseptable to wind damage.
If your roof is otherwise in good condition the algae and moss can be killed and gently removed using our low-pressure chemical cleaning. Never use high pressure on a roof, as it will damage it and may even void your warranty. Companies like Owens Corning, GAF, and also the Shingle Manufacturers Association recommend a low-pressure chemical application using certain cleaners to restore shingles blighted by roof algae.