The bottom of a roof should have a ________ flashing where it meets a wall.

The correct answer is that the bottom of a roof should have a kickout flashing where it meets a wall. Kickout flashing plays an essential role in directing water away from the intersection of the roof and wall. This type of flashing is specifically designed to prevent water from running down the wall and behind the siding or other materials, which can lead to water intrusion and damage.

Kickout flashing is typically installed at the lower edges of a roof where it meets a vertical surface, ensuring that rainwater is effectively channeled away from sensitive areas. By moving water away from the wall, kickout flashing helps protect against issues such as mold growth, rotting, and structural damage, thereby extending the lifespan of both the roof and the wall materials.

In contrast, ridge flashing is used at the peak of a roof where two slopes meet, apron flashing is generally placed at the bottom edge of a sloped roof to direct water away from a wall, and pan flashing is usually found along the base of chimneys or other vertical structures to provide an effective barrier against water. While these flashing types serve specific purposes, kickout flashing is crucial for the particular scenario of a roof meeting a wall, making it the appropriate choice in this context.