Counter flashing is a roofing flashing installed over base flashing to direct water away from roof penetrations and wall intersections.

Counter flashing is a weatherproofing component used in roofing systems to protect joints where roofs meet vertical surfaces such as walls, chimneys, or parapets. It is installed over base flashing and is designed to shed water away from vulnerable seams, preventing moisture from penetrating the building envelope.

In construction applications, counter flashing is commonly embedded into masonry joints or attached to wall surfaces above the base flashing. Materials typically include galvanized steel, aluminum, stainless steel, or copper, selected based on durability, corrosion resistance, and project requirements. Proper overlap and secure attachment are essential to ensure effective drainage and long-term performance.

From a performance and maintenance standpoint, counter flashing plays a critical role in preventing leaks and extending roof lifespan. Poorly installed or missing counter flashing is a common cause of water intrusion and roof failure. Regular inspection and maintenance help ensure that counter flashing remains properly sealed and integrated with the roofing and wall systems.

Properly installed counter flashing can last decades and often outlives the roofing material it helps protect.

• Aluminum Flashing
• Base Flashing
• Cap Flashing