Why is it necessary to cut all four sides before removing sub flooring during ventilation?

Cutting all four sides before removing subflooring during ventilation is primarily important for maintaining safe and efficient working conditions for firefighters. When subflooring is cut on all sides, it allows for better airflow, which can help to release heat and smoke effectively. This process reduces the chances of creating less-than-ideal smoke and heat conditions that could hinder a firefighter's ability to complete their job effectively. By ensuring proper ventilation, it helps to stabilize the environment underneath the structure, minimizing the risk of flashover or other dangerous conditions. Additionally, a more controlled environment enables firefighters to work more safely and effectively while addressing any potential hazards.