How high must a ladder extend above a 4-foot trench?

The requirement for a ladder to extend above the edge of a trench is primarily a safety measure to ensure that individuals can maintain secure footing while accessing or egressing from a trench. If a trench is 4 feet deep, it is mandated that the ladder extends at least 3 feet above the upper edge of the trench. This ensures that workers have enough height to safely grip the ladder while moving in and out of the trench, minimizing the risk of slips or falls.

Extending the ladder beyond the top of the trench by this amount not only provides a secure handhold but also helps in maintaining balance as workers step on or off the ladder. Such guidelines are crucial in construction and excavation sites where trenching work is performed, reflecting best practices for worker safety and compliance with safety regulations.