ABSTRACT
We have experienced varying thermal degradation of roofing materials in Japan, because it is situated from the subarctic to subtropical zones. Then, much difference in degradation is expected among the places where roofing materials are used. In order to make durable roof systems or maintain them in a satisfactory condition for a long period, it is necessary to know how roofing materials degrade outdoors and to predict it exactly at the stage of specifying materials.
