The recommended thickness for aluminum strip roofing varies depending on the specific application and local building codes. Generally, aluminum strip roofing is available in thicknesses ranging from 0.018 to 0.032 inches (0.46 to 0.81 mm). For residential applications, a thickness of 0.024 to 0.028 inches (0.61 to 0.71 mm) is commonly used, while commercial buildings might require a thicker strip, around 0.032 inches (0.81 mm) for added durability and longevity. Always consult with a roofing professional or follow local building codes to determine the appropriate thickness for your specific project.