ABSTRACT
Glass reinforced polyester (GRP) is used extensively in building and construction, and life expectancy is one of the most important attributes when selecting where the material may be used. In the construction industry GRP is mainly used as a cladding exposed to the environment. The main effect of weathering on GRP is loss of appearance, with loss of mechanical properties being only of minor concern. The mechanisms of degradation of GRP that cause this loss of appearance are complex and involve at least three processes, including moisture, photo-oxidation and stress.
This paper analyses the performance of a range of GRP roofing sheets that have been protected by a range of different techniques and have been exposed at three different sites in Australia for a period of four years. The paper discusses the effects of different conditions (i.e. UV, temperature, humidity and stress) on GRP degradation, as shown by the loss of gloss, yellowing, fibre whitening and fibre prominence.
