What is the primary structural function of joists in construction?

Joists play a critical role in supporting flooring systems in construction. Their primary structural function is to bear the load that the flooring material places on them, distributing that weight across the supporting walls or foundations. This helps maintain the integrity and durability of the floor, preventing sagging or failure under weight over time.

By serving as a framework for the floor, joists ensure that the load, including furniture, people, and other elements, is adequately supported. This structural role is essential for creating safe and functional spaces within a building. While joists can contribute to other aspects of construction, such as affording some lateral stability and potentially connecting walls, their fundamental purpose is predominantly centered around providing support for flooring systems.