What distance from roof edges should air terminals be installed to meet safety standards?

The correct distance for installing air terminals from roof edges is 24 inches, which is considered safe and effective according to established lightning protection standards. This distance helps ensure that the air terminal can effectively intercept lightning strikes before they can reach the building's structure, while also minimizing the risk of lightning flashover to adjacent structures or components.

Installing air terminals too close to the edge of a roof could lead to potential lightning strikes that do not get adequately attracted and directed away from the building. The 24-inch distance creates a physical buffer zone that contributes to the overall effectiveness of the lightning protection system, allowing for proper grounding and reducing the chances of damage from electrical surges.

The choice of 24 inches is part of a strategy to enhance the safety and reliability of lightning protection systems, aligning with guidelines that consider both effectiveness in lightning interception and safety for building occupants and structures.