Manufactured products, such as fenestration systems and the materials comprising the systems, are often observed to degrade due to exposure to the elements of weather. While standard and nonstandard methods have been developed to provide a means of assessing the effect of weathering, questions often arise concerning the relationship of resultant test data with actual in-service performance. In view of the questions concerning the relevance of test data and the rapidly growing focus on quality assurance, there is strong interest in developing improved test protocols. Focuses on the key choices that must be made in the design of weathering tests and includes identification of the currently available methods used for weathering of fenestration systems and the primary short-comings of those methods.

KEYWORDS: year 1995, testing, windows, weather, window frames, materials, deteriorating, performance, designing, exposure, comparing, durability