Trapezoidal Insulated Sandwich Metal Roof Cladding Under Static Wind Uplift: Numerical Analysis

Metal roof claddings are greatly used in the roofing industry in New Zealand and around the globe due to their high strength-to-weight ratio and lightweight nature. Trapezoidal roof claddings are significantly used in New Zealand as they have excellent wind uplift performance. However, they have poor thermal performance. Therefore, they are used with thermal insulators like Polyurethane (PU) foam to improve their thermal performance. Trapezoidal roof cladding under static wind uplift has been greatly studied, but no study have been carried out to explore the wind uplift performance of trapezoidal insulated sandwich metal roof cladding. The study first establishes the superior thermal performance of the trapezoidal insulated sandwich metal roof cladding in comparison to the individual trapezoidal metal roof cladding. Further, the study develops a numerical model to examine the static wind uplift capacity of trapezoidal insulated sandwich metal roof cladding. The study found that the maximum permissible span increases with an increase in the depth of the insulator, the maximum permissible span remains constant for two-span claddings, and there is very little variation for the three-span insulated cladding at lower wind uplift pressure. Finally, load-span tables are proposed for the ultimate limit state failure. The load-span data can be used by the designers and engineers in choosing the appropriate span for the trapezoidal insulated sandwich metal roof cladding based on the depth of the insulation.