Which component is used to create a weatherproof seal on a roof?

The correct choice for creating a weatherproof seal on a roof is flashing. Flashing is a material, typically made of metal, that is installed at the joints and seams of a roof, particularly where different materials meet or where there are penetrations, such as chimneys, vents, or skylights. Its primary function is to direct water away from critical areas, preventing water from seeping underneath roofing materials and causing leaks or water damage.

Flashing is crucial in ensuring that the roof remains impermeable to moisture, which is necessary for the longevity of the roof and the overall structural integrity of the building. It is essential for managing water flow and is considered a best practice in roofing installations.

Other components, while they serve important functions, do not create the weatherproof seal like flashing does. Fascia serves as a decorative trim along the edges of the roof and helps to support gutters, while soffits are found underneath the eaves and assist with ventilation. Eaves are the parts of the roof that overhang the walls, providing shade and protection, but they do not directly contribute to sealing the roof against water infiltration like flashing does.