What method of attack is used to apply water to the hot gases by sweeping the ceiling with water to cool the gases in order to prevent a flashover?

The indirect attack method is effective in preventing flashover by applying water to cool the hot gases that accumulate near the ceiling. During this technique, firefighters utilize a sweeping motion to direct water onto the ceiling and upper surfaces of the compartment. This action allows the water to absorb heat from the hot gases, lowering their temperature and reducing the potential for a flashover.

By cooling the upper layer of gases, the risk of ignition is diminished, allowing for a safer environment for interior firefighting operations and improving the chances for occupants' survival in the case of structural fires. This method is particularly useful in situations where visibility and access to the fire source are limited, making a direct attack more difficult.

Other methods, such as a direct attack, involve applying water directly to the fire's main body, which might not be effective in cases where the fire is well-advanced and gases are heated. Flanking and supplementary attacks serve different tactical purposes and may not specifically address the prevention of flashover in the same efficient manner as an indirect attack does.