Valley Flashing

Definition

Valley flashing is a thin sheet metal used to line the valley of a roof, providing a waterproof barrier where two roof slopes intersect.

Purpose

Valley flashing is essential in roofing to prevent water from penetrating the roof at the valley, where the risk of leaks is higher due to the convergence of water from two slopes.

Examples of Use

• Residential Roofs: Installing valley flashing in the valleys of residential roofs to ensure a watertight seal and prevent leaks.
• Commercial Buildings: Using valley flashing in complex roof designs to manage water flow and protect the building interior.
• Historic Restorations: Replacing or installing new valley flashing in older buildings to maintain structural integrity and prevent water damage.

Related Terms

• Roof Valley: The internal angle formed by the intersection of two roof slopes.
• Roofing Membrane: A continuous layer used to prevent water penetration in roofing systems.
• Gutter: A channel at the edge of a roof that collects and directs rainwater away from the building.

Notes

Proper installation of valley flashing is critical to its effectiveness. It should be integrated with other roofing components to ensure a continuous waterproof barrier.

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