The corrosion resistance of hot dipped galvanized steel coils on roofing and exterior walls is enhanced through various design and treatment methods to ensure long-lasting durability and aesthetic appeal under various climatic conditions and environments. Here are several ways to improve the corrosion resistance of hot dipped galvanized steel coils:

1. Selecting the Right Zinc Coating Thickness: The thickness of the zinc coating directly affects the corrosion resistance of the steel coil. For roofs and exterior walls exposed to the elements, especially in areas with high humidity or salt exposure (such as coastal areas), a thicker zinc layer (e.g., above 200g/m²) provides stronger corrosion protection. In milder environments, a thinner zinc layer (e.g., 60g/m²) can be sufficient.

2. Surface Treatment Processes: Surface treatments of the hot dipped galvanized steel coil can further enhance its corrosion resistance. Common surface treatments include chemical passivation, painting, and anti-fingerprint treatment, which prevent the zinc layer from direct contact with the external environment, thereby slowing down the corrosion process.

3. Waterproof Design: A good waterproofing system in the design of roofing and exterior walls is key to improving corrosion resistance. Ensuring that water does not accumulate, especially at seams and in drainage system design, helps reduce water-related corrosion on the steel coil's surface.

4. Using Coating Protection: Applying an additional protective coating, such as polyurethane or acrylic coatings, on top of the hot dipped galvanized steel coil can further enhance corrosion resistance. These coatings prevent the intrusion of moisture and salts and effectively reduce UV damage to the zinc layer.

5. Regular Maintenance and Inspections: Regularly inspecting the hot dipped galvanized steel coils on roofs and exterior walls, cleaning the surface of debris, checking for damage or peeling zinc layers, and performing repairs or re-coating can help maintain long-term corrosion resistance.