Samples of reinforced and unreinforced PVC roofing membranes were studied using dynamic mechanical analysis and tensile testing. Preliminary work has shown that the glass-transition temperature provides an indication of the relative stability of the membranes and may assist in understanding the shattering phenomenon.
This study discusses the utility of using the glass-transition temperature in standards for the reinforced PVC roofing membranes. It is shown that Tg values are easily obtained from dynamic mechanical analysis (DMA) and that DMA should be considered in the standards for roofing membranes.
Based upon the characterization of samples from shattered roofs, as well as reinforced materials subjected to artificial weathering, recommendations for enhancing the ASTM Standard D4434 are presented.