A 'Flat Roof' Fall-Protection Plan
A four-person crew is replacing a low-slope EPDM roof (slope 1/4:12) on a vacant three-story apartment building. The roof edge is 34 feet above grade, and a 30-inch parapet exists on only two of the four sides. The roof has four 2-by-4-foot glass skylights with deteriorated curbs, one roof hatch, and no other access; the crew reaches the roof by a 32-foot extension ladder. The lead man's plan: set a warning line 6 feet back from the open edges, stage tear-off debris and new membrane rolls outside the warning line to save trips, cover the skylights with 3/4-inch plywood 'when we get to them,' and have the two laborers work without harnesses because 'nobody falls off a flat roof.'
1. Evaluate the lead man's fall-protection plan for the roof edges.
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The plan fails at the first question: what protects the men on the two open sides?
- Trigger: the roof is low-slope (1/4:12) and the edge is 34 feet above grade - well over the 6-foot threshold, so fall protection is required on every unprotected side.
- Warning line alone is not enough. On low-slope roofs the acceptable combinations are guardrail, safety net, or personal fall arrest, or a warning line system combined with one of those or with a safety monitoring system. A line by itself is not a system.
- The parapet does not help. At 30 inches it is below the required guardrail height and lacks a midrail, so all four sides are effectively open.
- Staging outside the warning line defeats it. Materials stored beyond the line put workers at the very edge and create trip hazards - the exact behavior the line exists to prevent.
- If a safety monitor is used, that person must be competent, assigned no other duties, and remain on the same walking/working surface, able to see and warn each employee.
For a 34-foot edge, a guardrail system or personal fall arrest with engineered anchorage is the defensible answer.
2. How must the four skylights be handled, and when?
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Before any work begins on that roof - not 'when we get to them.'
- The rule: each employee on a walking/working surface must be protected from falling through holes, and skylights are holes, more than 6 feet above a lower level, by personal fall arrest, a guardrail system, or a cover.
- Cover requirements: the cover must be capable of supporting at least twice the weight of employees, equipment, and materials that may be imposed on it, must be secured against displacement, and must be marked or color-coded (e.g., 'HOLE' or 'COVER').
- The deteriorated curbs matter: 3/4-inch plywood resting on a rotted curb is not a cover - it must bear on sound framing and be fastened or otherwise restrained. Fabricate the covers with blocking that spans to solid structure at each skylight.
- Sequence: install, secure, and mark all four covers at mobilizaton, verify them at the start of each shift, and remove only under fall protection when the glazing is replaced.
A glass unit that fails underfoot is indistinguishable from an open hole - and it will be the first thing an inspector or compliance officer looks at.
3. What else in this setup creates exposure, and what program elements are missing?
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Access: a 32-foot extension ladder to a 34-foot eave does not work - it must extend at least 3 feet above the landing, be set at roughly a 4:1 angle, and be secured against movement. Carrying membrane rolls or debris up a ladder violates three-point contact; use a hoist or rope and a designated material-access point at the hatch.
Missing program elements:
- A written, site-specific fall protection plan with a designated competent person.
- Employee training and documented familiarization with the equipment.
- A rescue plan and prompt rescue capability - a fall arrest system without rescue capability converts a fall into a suspension-trauma emergency. Check clearance below the anchorage; a 34-foot edge with a shock-absorbing lanyard can put a worker on the ground before the system activates.
- Anchorage rated to the required strength, inspected harnesses and lanyards, and a hard rule that the parapet is never used as an anchor point.
- Jurisdiction note: Illinois has no approved state plan for private employers, so federal OSHA governs this job; Illinois OSHA covers public-sector employees. Either way, the fall-protection standard is the baseline, not the ceiling.