How far must ladders extend above the landing surface they serve?

Ladders must extend a minimum of 3 feet above the landing surface they serve to provide adequate support and safety for individuals using the ladder. This extension allows users to safely grasp the ladder when transitioning from the ladder to the landing surface or vice versa. By having this additional height, it reduces the risk of losing balance or slipping while trying to climb off the ladder, thereby enhancing overall safety during operations.

Other extensions, such as 4 feet, 5 feet, or 6 feet, would be excessive and not necessary according to standard safety practices, which helps to streamline ladder design and use without compromising safety. Hence, the established requirement of 3 feet is both practical and effective in promoting safe ladder use.