ABSTRACT
The deteriorating effects of the weathering elements on building paints is mainly a surface phenomena. Masonry and wood paints have been exposed over two years to natural conditions in a Mediterranean climate and for periods up to 4000 hours in a UV/condensation weatherometer. The exposed surfaces were studied by following the decrease in gloss and by examining the surfaces by Scanning Electron Microscopy. The SEM technique suggests that the polymeric binder in the external surface-layer is highly degraded by the UV radiation and washed away by the rain leaving almost “naked” mineral fillers and pigments on the surface. This explains also the severe decrease in the gloss of the exposed paints.
