Single-unit (monolithic) roofing applied to flat roofs may seem “safer” to some roof workers, but the work is still at height and subject to many similar hazards and safety requirements as sloped roof work. Proper fall protection measures, personal protective equipment (PPE), and adhering to safe work practices can protect workers from fall hazards.
Roof workers installing, maintaining, or repairing flat roofs with a height more than 20 feet or using backward-pulling machinery, such as felt-layers need protection from falls. Fall protection measures can include one or a combination of the following:
- Personal fall protection.
- Standard railings and toe boards.
- Catch platforms.
- Eave barriers.
- Scaffold platforms.
- Parapets (24-inches high).
When the fall protection measures listed above are not used, mark the edges of the flat roof with headers and warning lines to notify workers of potential fall hazard areas using the following guidelines:
- Lay headers (sheets of roofing or other materials) no closer than five feet inside the edges of the roof and parallel to the roofline.
- Install warning lines no closer than five feet inside the roof edges and at a height of 34-to-45 inches.
- Place warning lines and headers around the entire roof perimeter.
- If warning lines and headers are used only in the work area, move them as the work progresses around the roof to provide a continuous warning to workers.
- Connect material handling areas, storage areas, and access paths on the rooftop with a clear access pathway formed by two warning lines
- When a pathway is not in use, fasten a rope, wire, or chain equal in strength to the warning line across the pathway entrance from the work area.
Warning lines have specification requirements that include:
- Warning lines can consist of rope, wire, or similar material with a tensile strength of at least 500 pounds.
- Flag warning lines with a highly visible material at six-foot intervals.
- Use sturdy fixed or portable stanchions that are designed to minimize tip over or displacement to support the warning lines.
- Attach the warning lines to each stanchion so they don’t slide and create slack between stanchions when you pull on them.
The fall protection measures listed above are required for workers who operate felt laying machines (or other equipment that is pulled backward) no matter the potential fall height. An exception to these measures is that the parapet must be at least 36 inches high and perpendicular to the direction of travel. When these fall protection measures are not in place:
- Place headers no closer than 10 feet and warning lines no closer than five feet from the roof edge in a perpendicular path along the direction of travel.
- If conditions prohibit the use of headers, move the warning lines no closer than 10 feet from the edge in a perpendicular path along the direction of travel.
- Never operate equipment that is pulled backward within three feet of the roof edge.
- Don’t store motorized riding equipment between the warning line and the roof.
Train all workers on the warning line and header system. Instruct workers to stay within the safe areas during work. Warning lines and headers may not be practical for work on the roof edge, or on narrow or unusually shaped roofs. In these cases, a qualified person must closely supervise the roof work.
Roofing work is hazardous; don’t take flat roof work for granted even though the work may appear to be safer. Follow the safety guidelines described above to prevent potentially dangerous or fatal falls when working atop flat roofs.