What is the maximum spacing for air terminals along the roof perimeter or ridge?

The maximum spacing for air terminals along the roof perimeter or ridge is 20 feet. This spacing is critical for ensuring effective lightning protection. Air terminals, also known as lightning rods, are strategically placed to intercept lightning strikes and provide a safe path for the electrical discharge to reach the ground.

Positioning air terminals too far apart can create areas where the protection is insufficient, potentially leaving sections of the building vulnerable to direct lightning strikes. By maintaining a maximum spacing of 20 feet, the system can ensure that all areas of the roof are adequately protected, minimizing the risk of damage in the event of a lightning strike. This standard is set to optimize both safety and effectiveness in lightning protection design.