Which type of protective feature must be implemented at a roof edge for safe material storage?

Implementing guard rails at a roof edge is essential for ensuring safety during material storage. Guard rails create a physical barrier that helps to prevent materials, tools, and personnel from accidentally falling off the edge of the roof. This is particularly important when working at height, where falls can result in severe injuries or fatalities.

Guard rails are designed to withstand a certain amount of force and are typically constructed to be sturdy and durable. By establishing this protective boundary, workers are made more aware of the dangers at the edge, and it reduces the risk of items being displaced or rolling off the edge during operations.

While other options like signage, padding, and netting might play roles in safety, they do not provide the same level of protection against falls as guard rails do. Signage can inform workers of hazards, and padding might protect against falls if they occur, but neither provides a barrier. Netting could be used in certain situations but is not as universally applicable or effective as guard rails in preventing the fall of materials or people from a roof edge. Therefore, guard rails are the key protective feature needed for maintaining safety when storing materials at height.