Ventilation: indoor and outdoor air exchange.Set vent on metal roof.

In the roof, there is a metal moisture-proof layer inside the roof to prevent water vapor from flowing through the metal layer.The solution is to fill the metal roof with insulation cotton, lay waterproof membrane on the metal roof bottom plate, and have ventilation nodes on the metal roof panel.

Bearing: Bear construction load, rainwater, dust, snow pressure and maintenance load.The bearing capacity of the metal roof slab is related to the section characteristics of the slab type, the strength and thickness of the material, the mode of force transmission, and the spacing of purlins (auxiliary purlins).

Fire prevention: in case of fire, the metal roof materials will not burn and the flame will not penetrate the metal roof panel.

Anti wind pressure: resist the local maximum wind pressure, and the metal roof panel will not be pulled off by negative wind pressure.The wind resistance performance is related to the buckle force of metal roof panel and fixed seat, and the density of fixed seat.

Sound insulation: prevent sound from outside to inside or from inside to outside.The sound insulation material (usually made of insulation cotton) is filled in the metal roof layer. 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 sound insulation materials.It should be noted that sound insulation materials have different blocking effects on different frequencies of sound.

Lightning protection: lead the lightning to the ground to prevent the lightning from breaking through the metal roof and entering the room.

Heat preservation: prevent heat transfer on both sides of metal roof to stabilize indoor temperature.The insulation function is realized by filling thermal insulation materials (glass wool and rock wool commonly used) under the metal roof panel. The thermal insulation effect is expressed by U value, and the unit is w / m2k.The thermal insulation performance is determined by the following factors: the raw material, density and thickness of the insulation cotton; the humidity of the insulation cotton; the connection mode between the metal roof panel and the lower structure (to prevent the “cold bridge” phenomenon); the repeated ability of the metal roof layer to heat radiation.

Daylighting: improve indoor lighting through skylight during the day to save energy.When the lighting board or glass is arranged at the specific position of the metal roof, the service life of the skylight shall be coordinated with the metal roof panel, and the waterproof treatment shall be done at the joint of the skylight and the metal roof panel.