Roof Valley
A roof valley is the V-shaped channel where two sloping roof planes intersect, forming a natural pathway for water runoff.
Valleys handle more water volume than any other part of the roof, making them critical for waterproofing. DFW roofs use either open valleys (exposed metal flashing) or closed valleys (shingles woven or cut across the valley line). Open valleys are preferred in high-rain areas because they move water faster. After hailstorms, valley flashing damage often goes undetected until leaks appear during heavy rain.
Related Roofing Terms
Roof Flashing
Roof flashing is thin metal (aluminum, galvanized steel, or copper) installed at roof joints, valleys, and penetrations to prevent water infiltration.
Ice and Water Shield
Ice and water shield is a self-adhering waterproof membrane installed on the roof deck in vulnerable areas such as valleys, eaves, and around penetrations before shingles are laid.