What is a bar joist?

A bar joist is specifically an open-web steel truss commonly used in construction to support roofs and floors. It is designed with a network of steel bars arranged in a web pattern, which makes it lightweight yet strong enough to bear heavy loads. This design minimizes the weight of the structure while maximizing the strength and stability, making it a preferred choice in many commercial and industrial buildings.

Bar joists are particularly significant in firefighting and building design, as they can affect how fire spreads and the structural integrity during a fire. Understanding the construction components like bar joists is crucial for firefighters, as it informs their tactics and safety measures when dealing with structural fires. Knowledge of these elements can help firefighters plan their approach to ventilation, access routes, and potential collapse zones during a fire response.