Aluminum alloy metal roofing system has been widely used in many fields in recent years, because in addition to its excellent characteristics, reasonable structure level and correct construction method play a vital role. The structural layer of the plate is mainly composed of aluminum alloy metal roof plate, insulation layer and metal bottom plate, which are subdivided from bottom to top:
- bottom structure board: generally using perforated aluminum plated zinc or galvanized molded steel plate, its thickness according to the purlin distance to design, the perforation rate is calculated according to the project. Support sound absorbent cotton and thermal insulation cotton, as well as decorative role.
- Structural purlin: generally use purlin and steel purlin, play the role of structural support and slope.
- Dust layer: Generally non-woven fabric, mainly used for dust prevention, laid on the surface of the roof bottom plate.
- Sound-absorbing cotton: glass fiber cotton is usually used, and its bulk density and thickness need to be determined according to calculation.
- Vapor insulation: Generally using polyester film or high density spunbonded polyethylene film, can also choose glass fiber wool (with moisture-proof veneer), vapor insulation can limit the water vapor inside the building into the roof, thus avoiding condensation phenomenon to the greatest extent.
- Insulation and sound insulation layer: rock wool is usually used, and its thickness needs to be determined according to calculation. It mainly plays the role of heat preservation and noise reduction, such as the noise after heavy rain and hail impact on the surface layer.
- Waterproof breathable film: high-density polyethylene non-woven fabric, block the invasion of wind and rain on the building structure, strengthen the building air tightness, water tightness at the same time, but also provide rare air permeability, so that the water inside the envelope structure is quickly drained, effectively avoid the formation of mold and condensate.
The thickness of the aluminum alloy metal roof panel is usually 0.4mm-1.2mm, and the panel is a layer directly in contact with the atmosphere and rain, which is of great significance to the waterproof design and treatment of the surface layer. The choice of vertical height, vertical direction and construction treatment of special joints all determine the waterproof effect of the roof.