Abstract
Black streaks, which destroy the appearance of asphalt shingle roof systems, are a growing problem in almost all part of the U.S. This discoloration, often mistaken for dirt or worn-out shingles, is actuall the reulst of algae growing on the roofing granules. The most common form of algae present on roofs is known as Gloeocapsa Magna. Although this problem is most serius in the Seaboard and Gulf states, as well as in the Pacific Northwest, it continues to invade other regions of the country. The presence of algae on a roof can have a number of detrimental effects, such as increased maintenance costs and reduced property value. Public awareness is increasing as products become available to fight this problem. After studying the problem for years, the authors' company has developed a thorough understanding of the problem and how to address it. This paper discusss the scope of the roof algae problem, some current attempts to prevent growth, and how the relatively new copper-containing granule works to provide an algae resistant roof. When properly blended with standard colored roofing granules, this copper granule works on the principle of providing a uniformly distriburted, controlled release of cupric ions. Reseach has led to a mathematical model of this controlled leach that correlates very well to real time exposure studies of the copper granules' performance.
Black streaks, which destroy the appearance of asphalt shingle roof systems, are a growing problem in almost all part of the U.S. This discoloration, often mistaken for dirt or worn-out shingles, is actuall the reulst of algae growing on the roofing granules. The most common form of algae present on roofs is known as Gloeocapsa Magna. Although this problem is most serius in the Seaboard and Gulf states, as well as in the Pacific Northwest, it continues to invade other regions of the country. The presence of algae on a roof can have a number of detrimental effects, such as increased maintenance costs and reduced property value. Public awareness is increasing as products become available to fight this problem. After studying the problem for years, the authors' company has developed a thorough understanding of the problem and how to address it. This paper discusss the scope of the roof algae problem, some current attempts to prevent growth, and how the relatively new copper-containing granule works to provide an algae resistant roof. When properly blended with standard colored roofing granules, this copper granule works on the principle of providing a uniformly distriburted, controlled release of cupric ions. Reseach has led to a mathematical model of this controlled leach that correlates very well to real time exposure studies of the copper granules' performance.
Date
9/1997
9/1997
Author(s)
J Jacobs; R Thakur
J Jacobs; R Thakur
Page(s)
99-103
99-103
Keyword(s)
algae resistant roof; asphalt shingle; blue green algae; ceramic coating; copper; Gloeocapsa; discoloration; granule;
algae resistant roof; asphalt shingle; blue green algae; ceramic coating; copper; Gloeocapsa; discoloration; granule;