Roof Cleaning Lisle, Illinois in DuPage County – The owner of this house did his homework by researching the cause of those dirty streaks and stains on his roof. He learned that they are NOT an indication that the roof is old and needs to be replaced. But instead the black streaks are from the excretion of algae commonly referred to as roof mold. In short, “it’s not old, it’s mold.” So with the intent to maximize the life of the roof and thus delaying the large cost of a roof replacement, the owner had the algae and dirty stains safety removed by a profession roof cleaner. The roof is now in a healthy condition with many more years of useful life expected.