What Is Galvanized Metal Roofing?

The metal roof refers to a roof form that uses a metal sheet as a roof material and combines a structural layer and a waterproof layer into one. There are many types of metal sheets, including galvanized sheet, aluminized zinc sheet, aluminum alloy sheet, aluminum-magnesium alloy sheet, titanium alloy sheet, copper sheet, stainless steel sheet, etc. The surface of the sheet can be painted, mainly PE / PE, SMP / PE, HDP \ PE, PVDF \ PE these four kinds of baking paint treatment, baking paint can strengthen the service life of the plate, respectively 5-8 years, 10-15 years, 15-20 years, 20-25 years or more.

Metal roof

Metal roofing refers to the use of metal

The thickness is generally 0.4 to 1.5 mm, and the surface of the board is generally coated. Due to the different materials and coating quality, the life of some boards can reach more than 50 years. There are a variety of shapes for making boards, and some are composite boards.

1.Vertical occlusal system

(1) The overall structural waterproof and drainage functions can fully engage the joints regardless of the shape of the building. The entire roof has no nail holes, which can freely expand and contract the roof when temperature changes, avoiding temperature stress, and eliminating system screws Hidden water leakage caused by fixing method.

(2) No chemistry required

Factors to consider in metal roof design

Load-bearing

Withstand construction load, rain, dust, snow pressure, maintenance load. The load-bearing performance of metal roof slabs is related to the cross-sectional characteristics of the profile, the strength and thickness of the material, the force transmission method, and the pitch of the purlins (secondary purlins).

Wind resistance

Resistance to the local maximum wind pressure, metal roof panels 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 base, and the spacing of the fixing base.

Soundproof

Prevent sound from being transmitted from outdoors to indoors or from indoors to outdoors. The metal roofing layer is filled with sound-insulating material (usually made of thermal insulation cotton). The sound insulation effect is related to the density and thickness of the sound insulation material. It should be noted that the sound insulation materials have different blocking effects on sounds of different frequencies.

Anti-seepage

Prevent rainwater from seeping into metal roof panels from the outside. Rainwater mainly enters metal roofs through overlapping gaps or nodes. To achieve the anti-seepage function, it is necessary to use a concealed fixing after using a sealing washer at the screw mouth, and use sealant or welding treatment at the overlap of the board. It is best to use a long board to eliminate the overlap. The parts are tightly waterproofed.

Lightning protection

Direct the lightning to the ground to prevent the lightning from penetrating the metal roof and entering the room.

lighting

Use skylights to improve indoor lighting during the day and save energy. When arranging daylighting plates or glass at specific positions on metal roofs, the life of skylights should be considered in coordination with metal roofing panels, and waterproofing should be done at the connection between skylights and metal roofing panels.

safety devices

Set up fixed facilities on the metal roof to protect the safety of construction workers and maintenance workers.

Anti-icicle

Prevent rain and snow from forming icicles at the cornices.

Beautiful

The metal roof has a good texture and pleasing colors.

Controlling thermal expansion and contraction

Control the contraction displacement and direction of the metal roof panel. Make sure that metal roofing panels are not damaged by the stress caused by thermal expansion and contraction in areas with large temperature differences.

Insulation

Prevents heat from being transmitted on both sides of the metal roof and stabilizes the indoor temperature. The insulation function is realized by filling insulation materials (commonly used are glass wool and rock wool) under the metal roof panel. The 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 thermal insulation cotton; the humidity of the thermal insulation cotton, the connection method of the metal roof panel and the substructure (to prevent the "cold bridge" phenomenon); the repeated ability of the metal roof layer to heat radiation .

Sound absorption

Reduce the reflection of sound and reduce the echo in the room. The sound absorption function is realized by laying sound-absorbing cotton on the bottom layer of the metal roof and punching holes in the bottom plate. The sound absorption performance of a metal roof is expressed by the sound absorption coefficient a.

Moisture-proof

Prevent water vapor from condensing in the bottom layer of the metal roof and the metal roof layer, and drain the water vapor in the metal roof layer. The solution is to fill thermal insulation cotton in the metal roofing layer, lay a waterproof membrane on the metal roofing floor, and have ventilable nodes on the metal roofing panel.

Fire prevention

When a fire occurs, the metal roofing material will not burn, and the flame will not penetrate the metal roofing plate.

ventilation

Air exchange indoors and outdoors. Provide vents on metal roofs.

Anti-Avalanche

Snow barriers are installed on metal roofs in snowfall areas to prevent snow from falling off suddenly.

Pollution-free

Metal roofing materials do not cause environmental pollution, and the surface of metal roofing panels is not lightly stained.

Normal life

The service life of the metal roof should be equivalent to that of the main building, such as 25 years, 50 years, and 100 years.

maintain

It is convenient for the maintenance of the metal roof during the use period and reduces the maintenance costs.

cost

Control the construction cost of metal roofs.