Building owners have a responsibility to protect people who venture on their roofs, according to OSHA. OSHA prescribed certain safety requirements that were introduced in January 2017. Among them are a raised warning line 15 feet from the roof edge, and a guardrail or cage around skylights.
OSHA has designated three work zones on low-slope roofs with unprotected edges that are four feet or more above a lower level. The extremely high danger zone (less than six feet from the roof’s edge) requires a protective feature such as a guardrail system, safety net system, personal fall protection systems (e.g., personal fall arrest, travel restraint, positioning system), or a 42-inch-high parapet.
Guardrails are typically installed six feet from the roof’s edge. If there is something near the edge like a condenser unit requiring periodic maintenance, then guardrails must be placed right up to the roof edge.