What is the function of a girder in floor framing?

The function of a girder in floor framing is to connect the joists. Girders are horizontal beams that are pivotal in distributing loads from the joists to the vertical supports, such as posts or columns. They are typically positioned perpendicular to the joists, providing structural support and stability to the flooring system. The arrangement of girders allows joists to span across them, which helps to create a robust framework for the floor.

Understanding this function is crucial for anyone involved in carpentry and structural framing, as it emphasizes the importance of proper joist and girder installation in ensuring the safety and durability of a building's floor system. The other options do not accurately describe the primary role of a girder; while girders can support walls indirectly by supporting the joists, their main responsibility lies in connecting and supporting the joists themselves, thus maintaining the structural integrity of the floor framing.