What angle should the straight/solid stream be directed at the ceiling when using an exterior fire stream?

When utilizing an exterior fire stream, directing the straight or solid stream at a high angle toward the ceiling is essential for several key reasons.

First, a high-angle application allows the stream to better reach and penetrate areas where the heat is concentrated, such as the ceiling or upper layers of smoke. This is beneficial because the flames and superheated gases tend to rise, so aiming high allows the water to address the source of the heat effectively.

Moreover, a high-angle stream promotes better distribution of water droplets over a larger area upon impact with the ceiling, helping to create a cooling effect in the environment. This can prevent flashover and improve visibility for firefighters. Water droplets falling from the ceiling can also assist in suppressing the fire, as they can hit the fire below and facilitate extinguishment.

Maintaining a high angle also ensures that the fire is fought from a safe distance, minimizing the risk of exposure to heat and smoke. This technique takes advantage of the natural movement of heat and smoke, optimizing the effectiveness of the firefighting efforts while ensuring the safety of the personnel involved.