I. Main Structural Materials: Building a Stable “Framework”
The main structure is the load-bearing core of a curtain wall. Its strength and resistance to aging directly determine the fundamental lifespan of the façade. Common materials include aluminium alloys, steel, and stainless steel. When selecting them, corrosion resistance and fatigue performance are key priorities.
- Aluminium Profiles: Choose High-Grade Alloys + Surface Reinforcement
Aluminium is widely used for curtain wall frameworks due to its light weight and workability. However, standard aluminium has limited corrosion resistance, so both alloy grade and surface treatment must be upgraded for long service life.
Use 6063-T6 or higher-grade aluminium alloy, which offers tensile strength above 260 MPa and yield strength ≥ 240 MPa. Compared with common 6061 alloys, it provides over 30% improvement in deformation and fatigue resistance—crucial for bearing self-weight and wind loads over decades.
Surface treatments are essential for corrosion protection:
- Fluorocarbon coating (≥ 40 µm) is recommended for coastal or industrial regions. It forms a dense protective layer against salt spray and industrial pollutants.
- Electrophoretic coating is suitable for dry inland areas due to its strong adhesion and UV resistance, ensuring over 20 years of non-fading, non-peeling performance.
- Steel & Stainless Steel: Focus on Rust Resistance and Strength Matching
For super-high-rise buildings or large-span façades, steel is required for enhanced structural capacity. Use Q355B or higher low-alloy high-strength steel. Its low carbon content and good toughness, combined with hot-dip galvanizing (zinc layer ≥ 85 μm), significantly reduce rusting.
Stainless steel should be used for load-bearing nodes and connectors. Choose 304 or higher, while 316L is recommended for coastal environments. The added molybdenum improves resistance to chloride corrosion, preventing pitting caused by sea wind and ensuring long-term joint stability.
II. Cladding Panel Materials: Balancing Protection and Anti-Aging
As the “skin” of the curtain wall, panels are directly exposed to the environment and must provide durability, weather resistance, and (for glass) transparency. Common materials include glass, stone, and metal panels.
- Glass Panels: Low-E Coating + Double-Glazing as Standard
Ordinary float glass is weak in impact resistance and UV protection, making it prone to spontaneous breakage and aging. Long-life curtain walls should use tempered glass, with five times the strength of regular glass and safe breakage behavior.
To enhance performance:
- Use Low-E coated glass, which reflects infrared and UV radiation, lowers energy consumption, and slows aging from direct sunlight.
- Adopt double glazing with a 12–16 mm cavity filled with argon gas. This improves insulation, reduces noise, and prevents internal condensation that can lead to mold.
For typhoon-prone regions, upgrade to laminated tempered glass, where a PVB interlayer keeps shattered pieces bonded together, preventing falling hazards.
- Stone & Metal Panels: Improve Density & Surface Protection
Stone panels should be high-density granite (≥ 2.6 g/cm³), such as G654 or Rusty Yellow. These stones have low porosity and strong freeze-thaw and weather resistance. Before installation, apply six-side protective treatment using penetrating sealants to block internal pores and prevent efflorescence or cracking from moisture infiltration.
Metal cladding, typically aluminium solid panels, should use 3003-H14 aluminium with a fluorocarbon coating (three-coat, two-bake). This finish provides uniform gloss and outstanding weather resistance, maintaining stability even in extreme temperature conditions (–40°C to 60°C) without bubbling or peeling.
III. Sealing & Waterproofing Materials: Preserving the “Leak-Proof Lifeline”
Water leakage accelerates structural aging, making sealants and waterproof components decisive factors in curtain wall durability. Low-cost, low-quality materials must be avoided.
Use neutral silicone structural sealant, which offers strong adhesion, high elasticity, and movement capability ≥ 20%. Always verify the “three certificates”: factory certificate, test report, and compatibility report, to avoid failure from counterfeit materials.
For panel joints, pair the sealant with EPDM rubber gaskets. EPDM provides far superior aging resistance compared with ordinary rubber and can last over 25 years even under UV exposure and long-term moisture. Installation must ensure tight contact with the profiles, with no gaps left.
At the top and bottom of the curtain wall, install drainage plates and weep holes, using stainless steel drainage components to prevent corrosion and blockage, ensuring efficient and continuous water discharge.