ICC Commercial Building Inspector Practice Test

For metal-lined open or exposed valleys, what is the minimum width required for the valley lining?

1. 12 inches

2. 18 inches

3. 24 inches

4. 30 inches

The correct answer is: 24 inches

The minimum width required for metal-lined open or exposed valleys is 24 inches. This specification is important because the valley is a critical area in roofing where water runoff is concentrated. A wider valley lining ensures that the water is effectively channeled away from the roof structure and reduces the risk of leaks or water damage. Additionally, using a minimum width of 24 inches provides enough surface area to accommodate the flow of water during heavy rains, helping to minimize the potential for pooling or overflow, which could lead to deterioration of the roofing materials over time. Ensuring compliance with these dimensions is essential for maintaining the integrity and longevity of the roofing system.