What is the primary purpose of flashing on a roof?

The primary purpose of flashing on a roof is to prevent water leaks. Flashing is typically made of metal or another waterproof material and is installed in areas where the roof structure meets vertical surfaces, such as walls, chimneys, or skylights. It directs water away from these vulnerable points and ensures that any water that flows down the roof is channeled safely to the gutters. By effectively guiding water around potential entry points, flashing helps to maintain the roof's integrity and protects the underlying structure from water damage and leaks.

While insulation, shingle adhesion, and structural support are important aspects of roofing, they are not the primary function of flashing. Flashing specifically addresses the need for waterproofing critical areas where water may otherwise accumulate or seep in, which is essential for maintaining a dry and safe building.