Progress in the Development of a Thermal-Shock-Resistance Factor for Bituminous Built-Up Roofing Membranes
SourceThe resistance of bituminous built-up roofing membranes to thermally induced forces is considered in terms of their strength properties such as breaking load in tension, modulus of elongation, and apparent linear-thermal-expansion coefficient. The development of a thermal-shock-resistance factor is described and values are given for three bituminous built-up membranes at temperatures of -30 F (-34.4 C), 0 F (-17.8 C), 30 F (-1.1 C), and 73 F (22.8 C). The apparent relation between the values obtained in the laboratory and the observed performance of roofing membranes in service is considered. The utilization of the thermal-shock-resistance factor in the reduction of potential failures of bituminous built-up roofing membranes in service from thermally induced forces is also discussed.