What type of flashing should be installed where a roof-wall flashing exists and the roof terminates on the wall?

The installation of kickout flashing is essential where a roof terminates against a wall, particularly where roof-wall flashing is present. Kickout flashing directs water away from the wall and helps prevent water from running down the wall, which can lead to potential leaks and water intrusion. This type of flashing is designed to "kick out" the water that flows down the roof, ensuring it drains effectively away from the building's interior and foundation.

Proper installation of kickout flashing is critical because it serves to extend the roof’s drainage plane and prevents standing water or moisture accumulation at the wall intersection. When kickout flashing is omitted, the risk of water pooling and penetrating the wall increases, potentially causing damage to both the exterior and interior structure.

The other types of flashing listed serve different specific functions: counter flashing is utilized primarily with masonry walls to prevent water from entering at the joint; step flashing is interlaid with the shingles to help prevent water intrusion at roof-to-wall transitions; and base flashing is installed at the base of vertical surfaces, like walls, to safeguard against water entry at lower edges. Each type has its unique application, making the distinction important for effective roofing and waterproofing.