What type of edge is placed on architectural metal work to force the water to drip away from the wall?

The term "drip edge" refers to a specific feature that is designed to manage water runoff in architectural metal work. A drip edge is typically an overhanging element that directs water away from surfaces, effectively creating a barrier that prevents moisture from running directly down the wall. This is crucial for maintaining the integrity of the building's structure and preventing water damage.

In architectural applications, the drip edge's unique shape encourages water to drip off rather than follow along the edge, creating a controlled drainage path. This helps protect not just the metalwork itself, but also the materials behind it, mitigating potential issues like mold, rot, or degradation over time.

While other types of edges, such as hemmed edges or double hems, may serve functions of securing the metal or creating smooth finishes, they do not specifically address the management of water runoff in the same manner that a drip edge does. Therefore, the focus on directing water away from walls clearly positions the drip edge as the correct answer.