What is the minimum slope for lapped, nonsoldered seam metal roof panels without applied lap sealant?

The minimum slope for lapped, nonsoldered seam metal roof panels without applied lap sealant is 3 units vertical in 12 units horizontal. This specification is essential for ensuring proper drainage and minimizing the risk of water infiltration.

When metal roofs are installed with insufficient slope, water can accumulate at the seams, increasing the likelihood of leaks and degrading the performance of the roofing system over time. A slope of 3:12 provides a balance that allows for effective drainage while also accommodating the structural and aesthetic aspects of the installation.

Higher slopes, such as 4:12 or 5:12, might be found in specific applications or materials but are not the minimum required for nonsoldered installations. The 2:12 slope is generally considered too low for these types of panels without additional sealant measures, as it may not facilitate adequate runoff and could lead to performance issues. Therefore, 3:12 is the most appropriate choice that meets the minimum requirements for this roofing installation.