Weathering of roofing materials – An overview

TitleWeathering of roofing materials – An overview
Publication TypeJournal Article
Year of Publication2008
AuthorsPaul H Berdahl, Hashem Akbari, Ronnen M Levinson, William A Miller
JournalConstruction and Building Materials
Date Published04/2008
Keywordscool roof, Heat Island, Photodegradation, Roofing materials, Soiling, Solar reflectance, Weathering

An overview of several aspects of the weathering of roofing materials is presented. Degradation of materials initiated by ultraviolet radiation is discussed for plastics used in roofing, as well as wood and asphalt. Elevated temperatures accelerate many deleterious chemical reactions and hasten diffusion of material components. Effects of moisture include decay of wood, acceleration of corrosion of metals, staining of clay, and freeze-thaw damage. Soiling of roofing materials causes objectionable stains and reduces the solar reflectance of reflective materials. (Soiling of non-reflective materials can also increase solar reflectance.) Soiling can be attributed to biological growth (e.g., cyanobacteria, fungi, algae), deposits of organic and mineral particles, and to the accumulation of fly ash, hydrocarbons and soot from combustion.