What is the purpose of cap flashing in roofing?

Cap flashing serves a crucial role in roofing systems, specifically designed to prevent water from migrating behind base flashing. This is important because water intrusion can lead to severe damage, including structural integrity issues, mold growth, and degradation of roofing materials.

Cap flashing is typically installed at the junction of vertical and horizontal surfaces, such as walls and roofing, ensuring that any water that runs down the surface is directed away from the underlying structures. Proper installation of cap flashing creates a protective barrier, helping to divert water off the roof and away from areas where it could seep in and cause moisture problems.

Understanding this function is key for roofing professionals, as effective flashing is vital in maintaining the longevity and effectiveness of the roofing system. This also emphasizes the importance of proper installation techniques and material selection to ensure that the cap flashing performs as designed and effectively protects against water intrusion.