What is the minimum width of metal flashing recommended for open valleys?

The minimum width of metal flashing recommended for open valleys is 24 inches. This width is essential to ensure that water is effectively directed into the valley and that debris and other materials do not obstruct the flow of water off the roof. Proper flashing width also helps to prevent water from pooling or overflowing in heavy rain conditions, which could cause leaks or damage to the roofing system. Using 24 inches of flashing provides a sufficient surface area to accommodate the water flow from the adjacent roofing materials and maintain the integrity of the valley system over time. This standard helps ensure effective drainage and longevity of the roof, which are critical aspects of roofing design and installation.