Which flashing type is primarily used where a roof meets a wall?

The correct choice identifies roof-wall flashing, which is specifically designed for the critical area where a roof intersects with a vertical wall. This type of flashing is essential for preventing water from penetrating into the structure at these junctions, where the risk of leaks is heightened. The design of roof-wall flashing ensures that water is effectively directed away from the wall and onto the roof surface, maintaining the integrity of both elements.

Ridge flashing is utilized at the peak of a roof where two slopes converge but does not address the intersection of a roof and a wall. Valley flashing is installed in the valleys of a roof, directing water flow down towards the gutters but is not related to wall intersections. Drip flashing, while important for directing water away from surfaces like doors or windows, does not specifically cater to the roof-wall junction. Thus, roof-wall flashing stands out as the clear choice when it comes to managing water in the area where a roof meets a wall.