Removing roof algae is vital to keep your shingles healthy. Roof algae can destroy your shingles, and lower the life of a 30 year shingle down to 12-15 years. Outside of the ugly nature of the streaking on your roof, roof algae can simply eat away at the limestone in your shingles. The effect of having your roof washed is that is will kill and remove the roof algae and therefore increase your curb appeal and the length of time your roof will last.
At some point in recent history, some geniuses decided to stop using felt paper in their shingles and started using fiberglass. They quickly realized that the fiberglass wasn’t heavy enough and would blow loosely in the wind. It was also far to light for the minimum standards set at the time. Then an even smarter genius decided they’d use powdered limestone (an organic ingredient) to add some weight. Not a great idea as the algae love to feast on it.. Don’t be scared though, as the algae don’t necessarily degrade the shingles. They’re just very unsightly.
Cleaning the roof will cost about 10% of buying a new roof, but most homeowners don’t know that they can have their roof cleaned!