Anti-seepage: Prevent rainwater from seeping out into metal roof panels. Rainwater enters the metal roof mainly through overlapping cracks or joints. To achieve anti-seepage function, it is necessary to use a concealed fixed gasket at the screw opening, sealant or welding treatment at the overlap of the plate, preferably a long plate to eliminate overlap, and waterproof treatment with tight abdominal distension at various joints.
Fire prevention: metal roofing materials will not burn in case of fire, and fire will not penetrate metal roofing.
Wind pressure: Resist the maximum local wind pressure, metal roof panel will not be pulled off by negative wind pressure. Wind resistance is related to the buckling force of metal roof panel and fixing seat and the density of fixing seat.
Sound insulation: Prevent sound from outdoor to indoor or from indoor to outdoor. Sound insulation material is filled in the metal roof layer (usually made of insulating cotton). The sound insulation effect is expressed by the difference of sound intensity on both sides of the metal roof layer. The sound insulation effect is related to the density and thickness of the sound insulation material. Attention should be paid to the fact that sound insulation materials have different effects on different frequencies of sound.
Ventilation: Air exchange indoors and outdoors. A vent is arranged on the metal roof.
Moisture-proof: prevent the condensation of water vapor in the metal roof floor and the metal roof layer, and drain away the water vapor in the metal roof layer. The solution is to fill the metal roof with insulating cotton, lay waterproof film on the metal roof floor, and have ventilated joints on the metal roof panel.
Bearing: Bearing construction load, rainwater, dust, snow pressure, maintenance load. The load-bearing performance of metal roof panel is related to the section characteristics of the plate, the strength and thickness of the material, the mode of force transmission and the spacing of purlin (sub purlin).
Lightning protection: Lightning is directed to the ground to prevent lightning from breaking through metal roofs and entering the room.
Insulation: prevent heat transfer on both sides of the metal roof, so that the indoor temperature is stable. The thermal insulation function is realized by filling the thermal insulation material (glass wool, rock wool) under the metal roof panel. The thermal insulation effect is expressed in U value in W/M2K. The thermal insulation performance is determined by the following factors: the raw material, density and thickness of the thermal insulation cotton; the humidity of the thermal insulation cotton; the connection material between the metal roof panel and the_layer structure; the ability of the metal roof layer to repeat heat radiation.
Daylighting: Improve indoor lighting through skylights during the day to save energy. In order to arrange daylighting panels or glasses in specific positions of metal roofs, the service life of skylights should be coordinated with metal roofs, and waterproofing treatment should be done at the joint of skylights and metal roofs.
Beauty: Metal roof has good texture and pleasant color.
Controlling thermal expansion and contraction: Controlling shrinkage displacement and direction of metal roof panel. Ensure that the metal roof panel will not be damaged by the stress caused by thermal expansion and contraction in areas with large temperature difference.
Anti-avalanche: The metal roofs in snowfall areas are equipped with snow barriers to prevent the sudden fall of snow.
Anti-icing pillar: prevent rain and snow from forming icing pillars at the eaves.