Valley metal may have a crimped section down the center to help prevent _____.

Valley metal often includes a crimped section down the center primarily to prevent crosswash. Crosswash occurs when rainwater or melting snow flows from one side of the valley to the other, potentially bypassing the valley’s drainage system and causing water to drip or run off incorrectly. By incorporating crimping into the valley metal design, the flow of water is effectively directed, minimizing the risk of crosswash where water may be diverted inappropriately off the roof surfaces.

The crimped design helps manage water flow within the roofing system, ensuring that the water is channeled into the gutters or downspouts as intended, rather than creating unintended leaks or issues elsewhere on the roof or within the home. This is crucial for maintaining the integrity of the roofing structure and protecting the building from moisture damage.