A fire-cut refers to what type of cut made on a joist?

A fire-cut refers to an approximately 30-degree cut made on a joist, which is specifically designed to enhance the structural integrity of the building during a fire scenario. This type of cut is important because it allows the joist to fall away cleanly under the weight of collapsing materials during a fire, reducing the risk of overhead hazards for firefighters and improving safety while also allowing for better heat ventilation and smoke control.

The angle is critical; an approximate 30-degree cut lets the joist break loose at a more favorable angle rather than breaking the joist at a perpendicular or entirely different angle which could compromise the structural framework. Furthermore, using this technique is essential for effectively managing the dynamics of fire spread and heat buildup in a burning structure, highlighting the importance of understanding the specific purposes of various cuts in firefighting tactics.