The variations in outdoor weather conditions in Southern Africa are related to the geography of the country and the influence of these different conditions on organic materials is discussed.

The visual changes in a series of organic building materials that have been exposed to different climates for 6 years are recorded and commented on without attempting to elucidate the mechanism of degradation.

The physical changes that occur as a result of exposure in polychloroprene rubber sheets that originally conformed to standard specifications, are detailed and discussed.

The effectiveness of various ultraviolet (UV) absorbers on the rate of degradation of polypropylene under conditions of natural and accelerated artificial exposure is discussed.

The overall suitability of organic building materials for use under South African conditions are discussed and recommendations made.