Russ Spence
Commercial Pressure Wash Expert
Roof Stains
Roof Stains: Origin
Cyano bacteria has existed on earth for millions of years. Bacteria spores are carried by wind, birds, squirrels, etc. The roof stains are caused by the airborne spores from blue / green algae (Cyano Bacteria). These roof raiders land on your roof shingles and feed on the limestone base of the asphalt the shingles. The fungus, mold and mildew grow on the roof algae, as they require organic food (the algae) to survive.
Prior to 1978, cyano bacteria would starve to death when it landed on your roof:
After 1978 limestone was added to shingles, and limestone is a favorite food for algae, "cyano bacteria gloeocapsa".
So when wind and birds spread algae to your roof, it thrives on your roof by eating it!
Roof Stains: Survival
Bacteria Gloeocapsa, an airborne bacteria that is spread from one house to another by wind and animals (birds, squirrels).
Roof algae needs three criteria to grow: Heat, moisture, and nutrients.
Your home's roof, provides sun, rain, and limestone in the shingles. Everything to support a colony of bacteria.
Once the algae / bacteria are in place, fungus and mold arrive! Mold, Mildew, Lichens feed on the roof algae.
The fungus and mildew, would not survive without the roof algae / bacteria, and the roof algae / bacteria survives, because new asphalt shingles are made from limestone.
Roof Stains: Rapid Spread
As the roof algae grows, it holds moisture allowing the growth to accelerate.
Thus the roof streaks and stains spread wider and darker over time.
The spread of roof algae, mold, mildew and associated roof fungus extends throughout the country.
Originally believed to be primarily a Southeastern issue, the spores have been found to survive in some of the harshest climates.
Even shingle manufacturers have indicated that 80 percent of the asphalt shingle roofs in the United States are streaked or showing signs of being affected.
An estimated 40 percent of shingle roofs in Minnesota, have an shingle algae problem.
Extreme temperatures won't prevent the roof streaks spread, extreme heat or cold make them dormant until more favorable weather returns.
Roof Stains: What to do?
At the first sign of roof algae/fungus streaks, it makes good sense to clean your roof! Here's why: As the roof algae and fungus grow on your roof, they eat away the base of the shingle and expand and contract with the outside temperature. This growth and movement loosens the granules, creating premature granule loss, dramatically shortening the life of your roof. A 25-year roof may not even last 15 years if nothing is done. Failure to remove the roof algae will raise roof temperatures by preventing the reflective capabilities of the granules from doing their job. These temperatures make your air conditioner work a lot harder and increase your electric bills sometimes as much as several hundred dollars a year.
Roof Stains: Origin
Cyano bacteria has existed on earth for millions of years. Bacteria spores are carried by wind, birds, squirrels, etc. The roof stains are caused by the airborne spores from blue / green algae (Cyano Bacteria). These roof raiders land on your roof shingles and feed on the limestone base of the asphalt the shingles. The fungus, mold and mildew grow on the roof algae, as they require organic food (the algae) to survive.
Prior to 1978, cyano bacteria would starve to death when it landed on your roof:
After 1978 limestone was added to shingles, and limestone is a favorite food for algae, "cyano bacteria gloeocapsa".
So when wind and birds spread algae to your roof, it thrives on your roof by eating it!
Roof Stains: Survival
Bacteria Gloeocapsa, an airborne bacteria that is spread from one house to another by wind and animals (birds, squirrels).
Roof algae needs three criteria to grow: Heat, moisture, and nutrients.
Your home's roof, provides sun, rain, and limestone in the shingles. Everything to support a colony of bacteria.
Once the algae / bacteria are in place, fungus and mold arrive! Mold, Mildew, Lichens feed on the roof algae.
The fungus and mildew, would not survive without the roof algae / bacteria, and the roof algae / bacteria survives, because new asphalt shingles are made from limestone.
Roof Stains: Rapid Spread
As the roof algae grows, it holds moisture allowing the growth to accelerate.
Thus the roof streaks and stains spread wider and darker over time.
The spread of roof algae, mold, mildew and associated roof fungus extends throughout the country.
Originally believed to be primarily a Southeastern issue, the spores have been found to survive in some of the harshest climates.
Even shingle manufacturers have indicated that 80 percent of the asphalt shingle roofs in the United States are streaked or showing signs of being affected.
An estimated 40 percent of shingle roofs in Minnesota, have an shingle algae problem.
Extreme temperatures won't prevent the roof streaks spread, extreme heat or cold make them dormant until more favorable weather returns.
Roof Stains: What to do?
At the first sign of roof algae/fungus streaks, it makes good sense to clean your roof! Here's why: As the roof algae and fungus grow on your roof, they eat away the base of the shingle and expand and contract with the outside temperature. This growth and movement loosens the granules, creating premature granule loss, dramatically shortening the life of your roof. A 25-year roof may not even last 15 years if nothing is done. Failure to remove the roof algae will raise roof temperatures by preventing the reflective capabilities of the granules from doing their job. These temperatures make your air conditioner work a lot harder and increase your electric bills sometimes as much as several hundred dollars a year.