What is the primary function of flashing in construction?

The primary function of flashing in construction is to prevent water ingress. Flashing is a protective barrier made of materials such as metal, plastic, or other waterproof materials, strategically installed to direct water away from critical areas of a building, such as roof edges, chimneys, windows, and wall penetrations. By directing water to flow away from these vulnerable points, flashing helps to safeguard the structure against moisture penetration, which can lead to issues such as mold growth, structural damage, and deterioration of building materials.

Thermal insulation, while important for energy efficiency, is not the role of flashing; it serves a different function related to maintaining comfortable temperatures within a building. Supporting structural elements also falls outside the scope of flashing, as its role is strictly in weatherproofing rather than in providing structural support. Although aesthetic appeal can be a factor during the design phase, it is not the primary purpose of flashing; its main role remains focused on protecting the building from water damage.