Galvanized steel sheets are not only used for wall panels but also as key materials in building envelope systems, having been widely applied for over 50 years. Its core value lies in high corrosion resistance: Galvanized steel plates treated by continuous hot-dip technology typically have a surface zinc coating of Z120 (120 grams of zinc per square meter) or G90 (US standard, approximately 0.90 ounces of zinc per square foot). Data from the International Zinc Association shows that under standard atmospheric conditions, the service life of such plates can exceed 40 years, and the maintenance interval can be extended by more than 70%. A typical case is the large industrial warehouse built in the United States in the 1970s. The galvanized steel sheet exterior walls it used still maintain an integrity rate of over 85% to this day, and the annual loss rate of the zinc coating is less than 1μm.
Cost-benefit analysis shows that its advantages are significant. Compared with ordinary carbon steel coated wall panels that require frequent maintenance (on average once every 5 to 10 years, with each maintenance costing about 80 to 120 yuan per square meter), although the initial purchase cost of galvanized steel sheets may be 15% to 25% higher, the full life cycle cost (estimated over a 50-year period) can be reduced by 30% to 40%. After a large logistics park in Jiangsu Province, China adopted hot-dip galvanized steel plate wall panels, the maintenance cost expenditure was close to zero within 15 years, and the estimated return on investment (ROI) exceeded 22%. The construction efficiency is also competitive. The standard width of the panels is mostly 1000mm or 1250mm, and the length can be customized to over 12 meters. The installation speed can be increased by 300% compared with traditional masonry walls, significantly reducing the construction period by more than 30%.
Physical properties and environmental adaptability are the basis for its wide application. The yield strength of galvanized steel sheets is typically between 250MPa and 550MPa, and the tensile strength can reach up to 700MPa. In areas with extreme wind pressure (such as coastal regions), high-strength galvanized sheets with a thickness of over 0.7mm are used, which can withstand wind loads of over 50m/s (wind pressure value > 2.5kN /m²). Thermal performance research in the MIT laboratory shows that its solar reflectivity can reach 0.65. If combined with an insulation layer (such as 100mm thick rock wool), it can effectively reduce the building’s cooling load by 25% to 30%. The actual measurement data of the Osaka Bay Industrial Zone project in Japan shows that in a highly corrosive environment with a salt spray concentration as high as 1000mg/m³, the G90 galvanized steel sheet only thinners by 28μm over 50 years, and the weight loss rate is lower than the industry standard of 5g/m²· year.
Based on comprehensive engineering data and market verification, galvanized steel sheets have demonstrated irreplaceable value in wall panel applications: they have established a core position through an extremely low annual corrosion rate (<1μm/ year), a service life over 40 years longer than that of ordinary coating materials, and a full life cycle cost savings rate of up to 30% to 40%. With the increase in the industrialization rate of construction (China has exceeded 25%), its standardized specifications (board width 1m-1.25m, length customizable up to 12m), installation speed 15 times that of traditional masonry, and its ultimate wind pressure bearing capacity that has withstood century-old wind tunnel tests (able to withstand a hurricane of 70m/s) and other advantages It will continue to drive it to maintain an annual growth rate of over 15% in the global enclosure structure market.