What determines whether guards are necessary near roof hatch openings?

The necessity of guards near roof hatch openings is primarily determined by the height of the roof edge above a surface. When the roof edge is elevated significantly, it poses a greater risk of falling for individuals accessing or working near the hatch. Guardrails or other safety barriers are essential at these heights to prevent falls, ensuring compliance with safety regulations and protecting employees.

The other factors, while they may play a role in safety considerations, do not directly influence the requirement for guards as critically as the height of the edge does. For instance, the distance from the nearest building may affect proximity but not the immediate hazard faced by someone at the hatch. Similarly, the width of the roof hatch relates more to access and functionality rather than fall protection, and the type of roof material does not impact the need for protection against falls from height. Therefore, the height is the key determining factor for the necessity of guards.