Counter Flashing

Counter Flashing is a critical part of a roof’s waterproofing system, especially in areas where the roof meets a vertical surface like a chimney, wall, or skylight. It serves as the top layer of a two-part flashing system and is installed over base or step flashing to create a watertight seal that protects the joint from water intrusion. This top piece is usually embedded into a groove, known as a reglet, that’s cut into the masonry and then bent down over the lower flashing. Its main role is to direct rainwater away from the roof-to-wall connection and prevent it from seeping behind the flashing system, which could lead to moisture damage inside the home. Without counter flashing, water can slip behind the wall or chimney during wind-driven rain or snow melt, potentially causing wood rot, mold, insulation damage, and even structural issues over time. This is especially important in climates with frequent rain, snow, or freeze-thaw cycles. For homeowners, choosing the right material is just as important as proper installation. Copper is one of the best materials for counter flashing because it’s highly durable, corrosion-resistant, and can last over 50 years with minimal maintenance. Overall, counter flashing is not just a small roofing detail—it’s an essential barrier that helps prevent expensive water damage and ensures your home stays protected for years to come.