Illinois Roofing Practice Exam 2026 – Complete Exam Preparation Guide

The width of ice dam protection typically needs to extend beyond the eaves to effectively prevent water from backing up under the roof surface and potentially causing leaks and water damage. In the case of a 6:12 roof, which has a relatively moderate pitch, various guidelines recommend that the ice and water shield should extend at least 24 inches beyond the interior wall line or beyond the eave, as is standard in many building codes.

In this scenario, the eaves extend 30 horizontal inches, so to determine a suitable width for ice dam protection, you would ideally add this distance of 30 inches to the standard minimum coverage required. Therefore, the total width would be 30 inches (the eave extension) plus an additional amount to ensure adequate coverage, typically around 24 inches.

When you add these measures together (30 inches + 24 inches), you arrive at a total of approximately 54 inches. This provides a buffer against potential ice dam formation by extending the protective layer adequately down the slope of the roof and beyond the eave line.

Thus, 54 horizontal inches stands out as the most appropriate width for ice dam protection in this case, as it sufficiently addresses the potential issues caused by ice dams while adhering to best practices in roofing