What is the purpose of making an angle cut on a wooden joist?

Making an angle cut on a wooden joist is primarily aimed at lessening wall collapse in the event of a fire. This cutting technique, often referred to as a "wedge cut," allows for more effective heat and smoke evacuation during a fire. When the wooden joist is angled, it can help prevent the joist from causing a wall to collapse by ensuring that the structural integrity is maintained longer, as it creates a collapse zone that is directed away from load-bearing walls. This is critical for firefighting operations and for protecting life safety, as it allows firefighters to maneuver more safely and effectively in a burning structure.

Additionally, while there are other functions that various cuts may serve in different contexts, such as aesthetics or moisture management, those do not align with the core safety objectives during fire scenarios in building construction and design.