What is valley flashing used for?

Valley flashing serves a crucial role in roofing systems by preventing water leaks at the intersections of roof planes, particularly where two slopes meet to form a valley. These valleys are naturally susceptible to water accumulation, especially during rain, which can lead to potential leak points if not properly managed. By integrating valley flashing into the roofing design, the water is directed down the valley and away from the underlying structures, thus protecting the integrity of the roofing and facilitating proper drainage.

The other options, while related to roofing components, do not accurately describe the specific purpose of valley flashing. Sealing windows relates to the installation of window flashings or seals, which is a different aspect of weatherproofing in construction. Similarly, while the edges of roofs may use other types of flashing or trim to prevent leaks, they do not utilize valley flashing specifically. Lastly, the consideration of skylights involves unique flashing systems designed to accommodate the specific design and function of a skylight, separate from the function of valley flashing.