valley underlayment self adhering membrane

The High-Volume Trough: Hydraulic Scour Dynamics and Flashing Metallurgy in Roof Valleys

• September 21, 2026
• admin

In complex steep-slope roof geometry, valleys are the most hydraulically stressed zones on the entire building envelope. A valley forms where two intersecting roof planes converge at an internal angle, creating a sloping trough. While standard field shingles shed water across an expansive two-dimensional plane, a valley concentrates the runoff of two entire roof slopes …