Fall-arrest systems provide protection for roof workers. Various forms of safety equipment are available, and guidelines are used to ensure they are installed and used properly.
More than 6 million people work at approximately 250,000 construction sites across the United States every day. Inspectors are likely to find fall-arrest systems at these locations, as well as in residences, where homeowners (or hired professionals) use them while doing roof work to replace a vent, fix a leak, or evict a family of squirrels, for instance. Workers fall as a result of unstable working surfaces, misuse or failure to use fall-protection equipment, and human error.
Specifically, fall-arrest systems are used to assist roof workers and builders in the following ways:
- They reduce the likelihood of serious injury or death associated with a fall. The injury (or death) of a worker may financially ruin the contractor through lawsuits and lost work.
- They reduce the need for outdoor railings and scaffolds, which get in the way of the job, and provide only incomplete protection by themselves.
- They reduce the time required for construction and repairs, as well as the associated costs. Workers who are protected are not as concerned with fall avoidance, allowing them more freedom to concentrate on the job.
Fall-Arrest System Elements
- roof anchors. These metal devices are attached to the upper part of the roof rafter or ridge board, where they clamp the safety cable or rope in place. Various types of anchors are available, and they each have different requirements. Some require sheathing and some do not; some are disposable and some are reusable. Their prices vary with quality. Installation requirements are as follows:
- Manufacturers recommend placement every 8 to 10 feet, and about 6 to 8 feet from gable ends. These distances are intended to avoid the possibility that the worker will swing like a pendulum if he or she falls.
- Workers should also stay within a 30-degree arc of either side of the anchor point. On most houses, this equals approximately 5 to 6 feet.
- restraints. These ropes or cables may be made from materials such as polypropylene or polyester. Some ropes are self-retracting, meaning they automatically withdraw from a housing unit as a worker moves away from the unit. Inside the housing unit is a brake that activates in case of a free-fall. These systems are generally expensive yet easy to use because slack rope does not interfere with work.
- lanyards. These synthetic webbing devices connect the lifeline to the rope-grab mechanism. They are available in sizes from 1 to 3 feet (though they should never be longer than 3 feet), and may come with or without a shock absorber.
The Rojen Roof Safety Pole® is a vertical pole designed to stop construction workers from falling off roofs on construction sites. Invented by Australian Bob Richards, the device has been tested and certified as an anchor point in accordance with AS1891.4.
The pole is a telescoping aluminum rod that extends approximately 4 feet (1.3 meters) above the roof. The cable that extends from the shaft, like a car seatbelt, is designed to reel in and out with ease unless it is pulled sharply, in which case it will brake. The safety pole itself is designed to withstand an impact of 2.1 tons. Two models are available:
- the temporary tradesman's model; and
- the vent pole model, which provides permanent roof anchorage, and also functions as the building's sewer gas ventilation pipe.
The following are general guidelines that should be followed by anyone attempting to work on a roof:
- Keep the roof clean. Dirt and debris can cause you to lose your footing. Be careful to avoid tracking dirt on your shoes onto the roof.
- Mark off the area below you to let people know you are working. It is very easy to drop a tool!
- Never attempt steep or high roof work if you are not a professional. Lifelong disabilities and death happen more often than you think.
- Never work on a roof while it is windy, raining or when the roof is otherwise wet.
- Secure power tools that are not being used with ropes or bungee cords. It is helpful to keep all tools in a large bucket suspended from the roof.
- Wear shoes with good traction.