Causes of Roof Stains

Walking into your home you look and wonder why your roof has coffee spills? Are you suffering from the stained roof syndrome? It's that dark staining that looks like someone spilled coffee up on your roof. This problem used to be associated with mildew in years past. Mildew is a by-product of fungi and mold. However, it has been determined that another microorganism has invaded roofs in the USA, particularly asphalt shingle roofs. This organism is an algae, Gloeocapsa magma. "Roof Alage" has experienced an explosive growth curve during the past 15 to 20 years quite by accident.

Why now? Why my Roof!!

A large number of homeowners who are experiencing these roof stain problems are doing so for the first time. Even though they live in areas where the climate has not changed, the problem appears out of the blue. In years past, the roof algae simply didn't have a food source. Until shingle manufacturers lowered production costs, and provided roof algae with its favorite food, limestone. Today's shingles contain massive amounts of food that the roof algae love to eat.

How in the world does limestone get into fiberglass shingles you might ask? It's simple. The limestone is added to the asphalt mixture as a filler or thickener. Years ago, this was not necessary, as an organic felt mat was used as the base for the shingles. This mat was saturated with asphalt and then coated with granules. Because of the absorptive qualities of the mat, it was able to soak up enough asphalt to give the finished shingle sufficient weight. The materials used for the mat were derived from the cotton rag scrap market.

Well, about 20 years ago this rag market dried up because of the widespread introduction of synthetic textiles such as nylon and polyester. The shingle manufacturers scrambled and decided to use fiberglass as a mat.

However, a problem quickly arose. The thin fiberglass mat didn't absorb asphalt like the old organic mat. Something had to be added to the asphalt to increase the weight of the shingle. BINGO! They decided to use limestone because it's plentiful and cheap. The rest of the story is being played out above on your roof.

The Party is over...

Until recently, homeowners needed Professional Roof Cleaners to eliminate the roof algae and remove roof stains. Recently, roof cleaners have been made available to Do-It-Yourself homeowners who want to save the expense of the roof cleaner. A variety of roof cleaners exist. Choose wisely, you want a cleaner that is quick, simple and effective.