Precautions for roof design of steel structure plant

Anti-seepage: Prevent rainwater from seeping into the metal roof panel from outside. Rainwater enters the metal roof mainly through lap joints or nodes. In order to achieve the function of anti-seepage, it is necessary to use a sealing washer in the screw port and adopt a hidden fixation. Use sealant or welding at the overlap of the board. It is best to use a long board to eliminate the overlap. Tight waterproof treatment for abdominal distension.

Fire protection: The metal roofing material will not burn in the event of a fire, and the flame will not penetrate the metal roofing panel.

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

Sound insulation: prevent sound from being transmitted indoors or from indoors to outdoors. Fill the metal roof layer with sound insulation material (usually made of insulation cotton), and the sound insulation effect is expressed by the difference in 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. It should be noted that sound insulation materials have different blocking effects on sounds of different frequencies.

Ventilation: Air exchange indoors and outdoors. Set up vents on the metal roof.

Moisture-proof: Prevent the condensation of water vapor in the bottom layer of the metal roof 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 thermal insulation cotton, lay a waterproof membrane on the metal roof bottom plate, and have ventilable nodes on the metal roof.

Load-bearing: bear construction load, rain, dust, snow pressure, maintenance load. The load-bearing performance of the metal roof panel is related to the cross-sectional characteristics of the plate type, the strength and thickness of the material, the force transmission method, and the spacing of the purlins (secondary purlins).

Lightning protection: Lead the lightning to the ground to prevent the lightning from penetrating the metal roof and entering the room.

Insulation: Prevent heat transfer on both sides of the metal roof, so that the indoor air temperature is stable. The thermal insulation function is realized by filling thermal insulation materials (commonly used glass wool and rock wool) under the metal roof panel. The thermal insulation effect is expressed by the 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 thermal insulation cotton; the humidity of the thermal insulation cotton, the connection method of the metal roof panel and the underlying structure (to prevent the "cold bridge" phenomenon); the repeated ability of the metal roof layer to heat radiation .

Daylighting: Improve indoor lighting through skylights during the day to save energy. When arranging daylighting panels or daylighting glass at specific locations on the metal roof, the service life of the skylight should be coordinated with the metal roof panel, and waterproof treatment should be done at the junction of the skylight and the metal roof panel.

Beautiful: The metal roof has a good texture and pleasing color.

Control thermal expansion and contraction: control the contraction displacement and direction of the 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 differences.

Anti-avalanche: Set up snow barriers on the metal roof in snowy areas to prevent the snow from falling off suddenly.

Anti-icicle: Prevent rain and snow from forming icicles on the cornice