Natural Weathering of Cool Coatings and its Effect on Solar Reflectance of Roof Surfaces

AbstractWith the aim of determining the changing in the reflectance of coatings submitted to weathering conditions, 20 specimens (cool and standard) were exposed to natural weathering for 18 months. Their spectral reflectances were measured in laboratory with a spectrophotometer each 3 months, and the solar reflectances were calculated for each sample. The results indicated a reduction in the coatings reflectance after weathering exposure for the analyzed period. The results suggest the need of developing coatings able to maintain their reflective characteristics over time, increasing the potential of solar radiation reflection by these surfaces, and the reduction of buildings heat gains