What is the primary function of a joist in construction?

The primary function of a joist in construction is to provide horizontal support. Joists are typically used in floor and ceiling assemblies to distribute the load they carry and ensure structural integrity. They run parallel to each other and are spaced evenly apart, forming a framework that supports the weight of the materials above them, such as floors or ceilings. This function is crucial for maintaining the overall stability of a structure and preventing sagging or failure under load.

Vertical support refers to elements like columns or posts, which are not the role of joists. Roof framing often includes rafters or trusses, which are different components focused on the upper structure. Foundation anchoring is handled by the foundation itself, which stabilizes the entire building but does not involve the function of joists. Thus, recognizing the role of joists as horizontal supports is essential in understanding their critical function in construction.