How far must air terminals be placed from ridge ends on pitched roofs?

In the context of lightning protection systems, the placement of air terminals (commonly known as lightning rods) on pitched roofs is critical for effective lightning strike protection. The requirement for placing air terminals at least 2 feet from ridge ends on pitched roofs is based on established safety standards and best practices in the industry. This distance ensures that the air terminals are positioned effectively to intercept and safely conduct lightning strikes away from the building's structure.

This spacing helps in ensuring that the lightning protection system provides adequate coverage, reducing the risk of lightning strikes potentially damaging the ridge of the roof or nearby areas. By having the air terminals set at this distance, the design also facilitates better dissipation of the electrical charge and minimizes the chances of side-flashes, which can be particularly hazardous.

The other distance options, such as 1 foot, 3 feet, and 4 feet, do not align with established standards for effective lightning protection on pitched roofs, which is why 2 feet is the designated and correct answer.