Parapets & Low Roof Edges
Many flat roofs have a short parapet wall around the edge. Workers may think it protects them, but a low parapet can act as a fulcrum for a fall instead of preventing one. Know when a parapet counts as fall protection and when it does not.
- Roofers
- HVAC & Service Techs
- Maintenance
Height rules
- OSHA's guardrail rules require a top rail about 42 inches (plus or minus 3 inches) high in construction (39 to 45 inches), with midrails or equivalent. In general industry, the top rail is 42 inches above the walking surface (1910.29). See Guardrail Systems.
- A parapet can serve as a guardrail only if it is at least 39 inches high in construction and strong enough to resist the required force.
- Many parapets are 12 to 30 inches high. These are not adequate fall protection; a person can trip over them or lean and fall.
Hazards
- Working near a low parapet to inspect, repair flashing, set equipment, or clean gutters.
- Tripping while stepping back or carrying materials.
- Mechanical equipment, vents and skylights near the edge. See Fragile Surfaces.
- Fall hazards when climbing over the parapet to reach ladders or work outside the wall.
Protection options
- Temporary guardrail systems that clamp to the parapet or stand on counterweights or bases, bringing the height to the required level. Follow the maker's instructions.
- Warning lines and monitors on low-slope roofs (construction only, with limits). See Warning Lines & Monitors.
- Personal fall arrest or travel restraint with anchors set back from the edge, and roof anchors in the structure. See Roof Anchors and Personal Fall Arrest Systems.
- Safe access: use roof hatches with guardrails or permanent ladders with cages or systems. See Roof Access Hatches.
- Keep ladders secure and extend them above the parapet when used for access.
Before you go on the roof
- Know the parapet height and its condition
- Look for loose coping stones, rotted wood and damaged flashing
- Plan your work area and set up edge protection first
- Keep materials away from the edge
- Check the weather and wind. Do not work in rain or ice
Standards & references
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