A PVC Soffit is used to enclose the exposed undersurface of the overhanging section of the roof of a house. The underside of the gap between the wall and the fascia board are filled in with the soffit. In popular use, soffit most often refers to the material forming a ceiling from the top of an exterior house wall to the outer edge of the roof, that is, bridging the gap between a home's siding and the roofline. The soffit is typically screwed or nailed to rafters.
From wall to fascia, the soffit exposure profile on a building's exterior can vary from a few inches to 3 feet or more, depending on construction. It can be non-ventilated or ventilated for cooling non livable attic space.