An enclosed chute of wood or similar material is required whenever materials are dropped more than how many feet to any point lying outside the exterior walls of a building?

The requirement for an enclosed chute to be utilized when materials are dropped from a height is governed by safety regulations designed to prevent accidents and ensure the safety of workers and the public. When materials are dropped from a significant height, there is an increased risk of serious injury or damage if they were to fall freely to the ground or to an area where people might be present.

In construction and safety regulations, the threshold of 20 feet is often established as a point at which the risk becomes considerably more dangerous. An enclosed chute mitigates these risks by controlling the path of the materials being dropped, thereby preventing them from causing harm to anyone outside the building's perimeter. This regulatory measure emphasizes the importance of safety protocols in construction environments.

Therefore, the specified height of 20 feet necessitates the use of an enclosed chute, reinforcing the idea that any operations involving the drop of materials from elevated points should be conducted in a manner that prioritizes safety and compliance with established guidelines.