What is the definition of a bar joist in construction?

A bar joist is defined as an open-web steel truss that is commonly used in construction to support floors and roofs. This design features a series of steel rods or members arranged in a triangular pattern, which allows for a lightweight and efficient structural system. The open-web design not only provides strong support over large spans but also allows for the passage of mechanical systems such as ductwork and plumbing through the webbing without compromising structural integrity.

In construction, using open-web trusses like bar joists is advantageous because they combine strength and efficiency while minimizing material use. Their design contributes to lower dead loads, which can lead to cost savings on structural supports and foundations. The versatility of bar joists makes them a popular choice for commercial and industrial buildings.