What type of flashing should be installed at the junction of a roof and a wall?

Wall flashing is the appropriate type of flashing to be installed at the junction of a roof and a wall. This type of flashing serves the important function of directing water away from the seam where the vertical wall meets the roof surface. Properly installed wall flashing helps to prevent water infiltration, which can lead to mold growth, structural damage, and other issues within a building.

In this context, wall flashing is designed to cover the top edge of the wall and extend up under the siding or other wall materials to ensure that any water that runs down the wall or from the roof is channeled away effectively. This is critical for maintaining the integrity and longevity of both the roof and the wall.

Other types of flashing, such as counter flashing, step flashing, and apron flashing, serve different purposes and are typically used in other contexts. Counter flashing, for example, is utilized to cover the top edge of base flashing and is often seen in areas where masonry meets a roof. Step flashing is generally used around chimneys and is applied in a step-like pattern to shed water away from the joint. Apron flashing is used at the base of walls to direct water away but is not specifically focused on the roof-wall junction like wall flashing is.