What is the function of a rafter in building construction?

The function of a rafter in building construction is to act as a roof beam that follows the slope of the roof. Rafters are structural elements installed from the ridge or top of the roof to the eaves or the sides of the building, providing support for the roof covering and transferring the weight of the roof down to the walls and ultimately to the foundation. This design allows for the effective shedding of water and snow, contributing to the overall integrity and performance of the building envelope.

The other options describe different components and their functions. For instance, a member that supports the foundation typically refers to beams or footings, which provide the base support of the structure. A wall stud that extends two stories high describes vertical framing members that support the wall system but is unrelated to roof support. Lastly, a component that frames the floor pertains to joists or beams that support the flooring system, which is distinct from the functions of rafters that specifically relate to the roof structure.