What is the name of the trim board applied to the lower edge of a sloping roof?

The trim board applied to the lower edge of a sloping roof is known as fascia. It serves both functional and aesthetic purposes. Functionally, fascia boards help support the lower edge of the roof and can also serve as a base for the gutter system, ensuring that rainwater is directed away from the building. Aesthetically, the fascia provides a finished look to the roofline, covering the rafter ends and creating a more polished appearance.

Other terms mentioned in the options refer to different components of a roofing system. The gutter is designed to collect and channel water away from the roof, the soffit is the material that bridges the gap between the edge of the roof and the wall of the house, often featuring ventilation to help regulate temperature in the attic, and eave refers to the part of the roof that overhangs the walls of the house. These components work together with the fascia, but they each serve distinct roles in roofing systems.