PVC roofing tiles are classified as Class B1 flame-retardant materials. According to the national standard GB 8624-2012, compliant products will soften and emit smoke when exposed to fire, but will self-extinguish once removed from the heat source and will not continue to burn. Fire resistance depends on the formulation. Reputable manufacturers add sufficient flame retardants to ensure a limiting oxygen index of 28 or higher, whereas substandard products contain insufficient flame retardants and thus have poor fire resistance. The fire resistance of mainstream PVC roofing tiles on the market...
