The ASTM D4434-2021 standard targets flexible roofing sheets made of polyvinyl chloride (PVC) (PVC) Resin, mainly for single-layer roofing films exposed to weather. The standard covers the physical performance requirements of the sheets, including total thickness, breaking strength, breaking elongation, joint strength, Tear strength, low temperature bending, performance retention after accelerated aging, etc. The standard does not address design criteria for on-site roofing systems, such as fire resistance and wind lift resistance, etc. Testing and performance limits are designed to ensure that the sheets meet minimum mass requirements. Users need to take appropriate safety measures according to the actual situation and ensure compliance with relevant regulations.