For roofs with a waterproof design life of 25 years or more, profiled steel plates should be used for the roof surface layer, and polyvinylidene fluoride (fluorocarbon PVDF) should be used as the coating type. For roofs with a waterproofing design life of 15 years or more, the roof surface layer should be made of profiled steel plates, and the coating type should be silicon-modified polyester or high weather-resistant polyester. The roof waterproofing design has a service life of 10 years and for temporary roofs, the surface and bottom layers are made of profiled steel plates, and the coating should be polyester.