What is Soffit?

Definition of Soffit in Construction

The bottom surface of any overhang, such as a cantilevered second floor, the underside of a normal roof overhang, the underside of a boxed out interior detail, or any horizontal ceiling surface that projects out from a vertical face. Soffits are used to ventilate attic spaces, ventilate interior enclosed boxed spaces, etc. The term soffit is also used to describe any box out of ductwork, sprinkler systems, cabling, etc. that is constructed, to provide protection for an interior construction component, that needs to be covered for code or aesthetic reasons. Soffit is used in many different manners on a construction site to describe a variety of surfaces. Best understood as simply any projection or box out that is set aside from the vertical wall or surface.