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Fall Protection Systems (Continued)

Fall Protection on Metal Roofs

Personal Fall-Restraint Systems

Unlike the personal fall-arrest system, which is designed to stop a fall, a personal fall-restraint system prevents a worker from reaching an unprotected edge and thus prevents a fall from occurring. The system consists of an anchorage, connectors, and a body harness or a body belt. The attachment point to the body belt or full body harness can be at the back, front, or side D-rings.

The anchorage for a fall-restraint system must support at least 3,000 pounds or be designed and installed with a safety factor of at least two. If you're not sure how much an anchorage will support, have a qualified person evaluate it.

Positioning-Device Systems

Positioning-device systems make it easier to work with both hands free on a vertical surface such as a wall or concrete form. Positioning-device systems are also called Class II work-positioning systems and work-positioning systems.

positioning device
Positioning device with self-retracting lanyard Click to enlarge.

The components of a positioning-device system - anchorage, connectors, and body support - are similar to those of a personal fall-arrest system. However, the systems serve different purposes.

A positioning-device system provides support and must stop a free fall within 2 feet; a personal-fall-arrest system provides no support and must limit free-fall distance to 6 feet.

  • Anchorage: Positioning-device systems must be secured to an anchorage that can support at least twice the potential impact of a worker's fall or 3,000 pounds, whichever is greater.
  • Connectors: Connectors must have a minimum strength of 5,000 pounds. Snap hooks and D-rings must be proof-tested to a minimum load of 3,600 pounds without deforming or breaking.
  • Body support: A body belt is acceptable as part of a positioning-device system. However, it must limit the arresting force on a worker to 900 pounds and it can only be used for body support. A full-body harness is also acceptable and must limit the arrest force to 1,800 pounds. Belts or harnesses must have side D-rings or a single front D-ring for positioning. All connectors must have locking features to avoid unclipping.

1. Which of the following systems makes it easier to work with both hands free on a vertical surface such as a wall or concrete form?

a. Personal fall-arrest system (PFAS)
b. Positioning-device system
c. Safety net system
d. Full-body harness system

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Guardrail Systems

Copyright:bialasiewicz / 123RF Stock Photo
Is this guardrail properly constructed?

A guardrail system consists of a top rail, midrail, and intermediate vertical member. Guardrail systems can also be combined with toeboards that prevent materials from rolling off the walking/working surface.

Guardrail systems must be free of anything that might cut a worker or snag a worker's clothing. Top rails and midrails must be at least 1/4-inch thick to reduce the risk of hand lacerations; steel or plastic banding cannot be used for top rails or midrails. Other requirements for guardrails:

  • Wire rope used for a top rail must be marked at least every 6 feet with high-visibility material.
  • The top rail of a guardrail must be 42 plus or minus 3 inches above the walking/working surface. The top-edge height can exceed 45 inches if the system meets all other performance criteria.
  • Midrails must be installed midway between the top rail and the walking/working surface unless there is an existing wall or parapet at least 21 inches high.
  • Screens and mesh are required when material could fall between the top rail and midrail or between the midrail and the walking/working surface.
  • Intermediate vertical members, when used instead of midrails between posts, must be no more than 19 inches apart.
  • A guardrail system must be capable of withstanding a 200-pound force applied within 2 inches of its top edge in any outward or downward direction.
  • Midrails, screens, and intermediate structural members must withstand at least 150 pounds applied in any downward or outward direction.

2. The top rail or a guardrail must be _____ inches plus or minus _____ inches above the walking/working surface.

a. 42, 3
b. 42, 5
c. 39, 9
d. 49, 3

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Safety-Net Systems

Safety nets saved lives during Golden Gate Bridge construction.

Safety-net systems consist of mesh nets and connecting components.

  • Safety-net openings can't be more than 6 inches on a side, center to center.
  • Safety nets must not be installed more than 30 feet below the working surface.
  • An installed net must be able to withstand a drop test consisting of a 400-pound sandbag, 30 inches in diameter, dropped from the working surface.
  • Inspect safety nets regularly and remove debris from them no later than the start of the next work shift.

The minimum horizontal distance to the net's outer edge depends on how far below the working surface the net is placed.

See the

Minimum Horizontal Distances

Net's distance below work surface Minimum horizontal distance from edge of working surface to net's outer edge
Up to 5 feet 8 feet
5 to 10 feet 10 feet
More than 10 feet 13 feet

3. Safety nets must not be installed more than _____ below the working surface.

a. 10 feet
b. 20 feet
c. 30 feet
d. 40 feet

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Warning-Line Systems

Copyright:bialasiewicz / 123RF Stock Photo
Warning line system with signage.

A warning-line systems consist of ropes, wires or chains, and supporting stanchions that mark off an area within which work can be done without guardrails, personal fall-arrest systems, restraint systems, or safety nets.

Warning-line systems can only be used for roofing work on roofs that have slopes of 2:12 or less, vertical to horizontal. The purpose of the line is to warn roofers that they are near an unprotected edge.

The warning line must be at least 6 feet from an unprotected edge and meet the following criteria:

  • Be flagged at least every 6 feet with high-visibility material.
  • Be rigged so that the line is 34 to 39 inches from the walking/working surface.
  • Have a minimum tensile strength of 500 pounds. Don't use plastic caution tape for a warning line.
  • Be attached to each stanchion so that tension on one section of the line will not cause an adjacent stanchion to tip over. Stanchions must be able to support a force of at least 16 pounds applied horizontally in the direction of the roof edge without tipping over.

Those who do roofing work between the warning line and an unprotected roof edge must be protected with personal fall-arrest systems, restraint systems, guardrail systems, safety monitoring systems, or safety nets.

4. While roofing work is taking place the warning line must be at least _____ from an unprotected edge.

a. 6 feet
b. 10 feet
c. 20 feet
d. 30 feet

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Image of roofer thinkstock photo
Will this alternative fall protection method stop a fall?

Residential Roof Construction

Employees engaged in residential construction activities 6 feet (1.8 m) or more above lower levels must be protected by guardrail system, safety net system, or personal fall arrest system unless another provision in 1926.501(b) provides for an alternative fall protection measure.

Exception: When employers can prove that it is infeasible or creates a greater hazard to use these systems, the following applies:

  • Employers and residential contractors are permitted to use alternative methods of fall protection where it is infeasible to use conventional means. Where infeasibility is proven, the contractors can implement a fall protection plan, as specified in section 1926.502(k).
  • There is a presumption that it is feasible and will not create a greater hazard to implement at least one of the three fall protection systems mentioned above.
  • Employers have the burden of establishing that it is appropriate to implement a fall protection plan for a particular workplace situation, in lieu of implementing guardrail, safety net systems, or fall arrest systems.

5. Employees performing residential construction activities _____ must be protected by fall protection systems.

a. at least 4 feet above ground level
b. 6 feet or more above lower levels
c. over 10 feet above a lower work surface
d. 12 feet or more above the ground

Next Section

Safety Monitoring for Roofing Work

OSHA Safety Monitor Image
Safety monitors must not be distracted.

When other fall protection methods are not feasible and a competent person has developed a written plan, safety monitoring systems may be used. This is a method in which a person, rather than a mechanical system, warns workers doing repairs when they are in danger of falling. The monitor, who must be a competent person, is responsible for recognizing fall hazards and warning workers about them. Safety monitoring systems must meet the requirements of OSHA 29 CFR 1926.502(h).

Safety monitoring can be used only to protect those who do roofing work on roofs that have slopes less than or equal to 4 in 12 (vertical to horizontal) and widths no greater than 50 feet. Safety monitoring on roofs wider than 50 feet is not permitted unless a warning-line system also protects the workers.

The safety monitor's responsibilities:

  • Recognize fall hazards.
  • Warn employees when they are unaware of hazards or aren't working safely.
  • Stay on the same walking/working surface as the workers to see them and to communicate with them while they are working.
  • Avoid any other work or distracting activity while monitoring the workers.

Only those who are doing roofing work are permitted in the area controlled by the safety monitor. Mechanical equipment can't be used or stored in the area.

6. The safety monitor used during roofing work must be a _____.

a. qualified person
b. competent person
c. member of the AGC
d. registered engineer

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Catch Platforms

A worker fell through this bridge catch platform due to missing planks.

Catch platforms, which consist of a stable platform and an attached standard guardrail, can protect roofers when other systems or methods are not feasible. Platform guidelines:

  • The platform should not be more than 18 inches below the eave line of the roof.
  • The platform should extend horizontally at least 2 feet beyond the eave line of the roof.
  • The platform must have a standard guardrail and toeboard. The top guardrail should rise substantially (at least 12 inches) above the eave line of the roof. Install intermediate rails or a solid barrier between the top rail and the platform to prevent a worker from sliding under the top rail.

Covers for Holes

Simple and effective when they're properly installed, rigid covers prevent workers from falling through skylights or temporary openings and holes in walking/working surfaces.

This skylight was not properly guarded.

Safety criteria for covers:

  • Will support at least twice (2 times) the maximum expected weight of workers, equipment, and materials. Skylights are not considered covers unless they meet this strength requirement.
  • Are secured to prevent accidental displacement.
  • Have full edge bearing on all four sides.
  • Are painted with a distinctive color or marked with the word HOLE or COVER.

Fences and Barricades

Fences and barricades are warning barriers, usually made from posts and wire or boards, that keep people away from hazards such as wells, pits, and shafts.

7. Hole covers will support at least _____ times the maximum expected weight of workers, equipment, and materials.

a. 2
b. 3
c. 4
d. 5

Next Section

Protecting Workers From Falling Objects

OSHA image - Lack of head protection
What we have here, is a failure to train.

You need to be aware of those working above or below you. Protect yourself and others from falling objects with one of the following methods:

  • Canopies: Make sure canopies won't collapse or tear from an object's impact.
  • Toeboards: Toeboards must be least 3½ inches high and strong enough to withstand a force of at least 50 pounds applied downward or outward.
  • Panels and screens: If you need to pile material higher than the top edge of a toeboard, install panels or screens to keep the material from dropping over the edge.
  • Barricades and fences: Use them to keep people away from areas where falling objects could hit them.

When doing overhand bricklaying, keep materials and equipment (except masonry and mortar) at least 4 feet from the working edge. When doing roofing work, keep materials and equipment at least 6 feet from the roof edge unless there are guardrails along the edge. All piled, grouped, or stacked material near the roof edge must be stable and self-supporting. No amount of precaution will work if employees do not use safe work practices.

8. Toeboards must _____.

a. be made of a water-resistant hardwood
b. not exceed 4 inches high and 2 inches wide
c. be least 3.5 inches high
d. be within 3 inches of a working-surface edge

Check your Work

Read the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.


Worker Fatality Investigations

This California Public Health video explains the events that led to a roofing supervisor's death after he fell 30 feet through a warehouse roof skylight onto a floor. Photographs from the fatality investigation are supplemented with scenes recreated by co-workers who were there that day.

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