Fall protection while installing roof trusses – dancing with danger.

OSHA fall protection roof truss installation

Accidental falls are the leading cause of death for construction workers. OSHA requires fall protection measures for residential construction activities 6 feet or higher above lower levels.

Over the years, we’ve had clients that either had an employee fall or knew a business where their employee fell to ground while either framing or installing a roof.  The consequence of the fall leads to serious injury and can be fatal.  Having a common sense fall protection plan and procedure is difficult when installing roof trusses.  I hope I will be able to help with some insight as it relates to employee safety during this phase of construction.

Roof trusses are the highest part of a house frame, and installing them can be particularly dangerous for two reasons:

  1. Truss construction usually occurs high above the ground.
  2. Trusses are not stable until they are properly restrained and braced.

Employers must plan ahead to ensure they have the right fall protection systems in place, and that all workers are properly trained before the job begins.

 

PFAS and Truss Installation

A personal fall arrest system (PFAS) is designed to safely stop a fall before the worker strikes a lower level. The system includes three major components:

  1. An anchorage to which the other components of the PFAS are rigged
  2. A full body harness worn by the worker
  3. A connector, such as a lanyard or lifeline, linking the harness to the anchorage. A rip-stitch lanyard, or deceleration device, is typically a part of the system.

Remember that workers must use full-body harnesses in fall arrest systems. Body belts can cause serious injury during a fall, and OSHA prohibits their use as part of fall arrest systems.

PFASs need strong anchor points that can hold the sudden weight of a falling worker. No anchor with a single connection point, such as a strap anchor or a bolt-on anchor, will protect a falling worker who is attached to a single truss.

Although PFASs are the most widely used form of fall protection in residential construction, they might not be suitable when workers begin installing roof truss sections because there may not be a stable place to attach an anchor. Trusses are designed to support weight from the top down. Until trusses are properly restrained and braced, they are weak if pulled from the side (i.e., subjected to lateral force) as can occur when a truss-mounted fall protection system bears the full weight of a falling worker.

Other systems, such as scaffolds, lifts and ladders, can be used to protect workers until a fully inter-connected, multi-truss section has been appropriately braced and secured.

 

Reducing Risks During Initial Truss Installation

Guardrails, nets or PFASs (conventional fall protection) may not be practical for all phases of truss installation. Instead, employers should plan to use other methods, such as ground assembly, scaffolds, aerial lifts or ladders to keep workers safe.

  • Ground assembly: By assembling a truss section on the ground, employers can greatly reduce the risk of falls for workers. A section of trusses can be sheathed while still on the ground. Peak anchors and lifelines can be pre-installed before the section is lifted into place. Many builders find it efficient to pre-assemble truss sections on the ground and then lift them with a crane so that workers can secure the section to the building frame.
  • Lifts: Depending on the building layout and the tasks involved, lifts (e.g., aerial, scissor) may be options for setting trusses. Lifts provide a stable, elevated platform from which workers can operate. Workers must follow all safety procedures and conduct all operations from inside the lift basket. For other requirements for using lifts, refer to 29 CFR 1926.453, Aerial Lifts.
  • Scaffolds: When properly constructed and used, internal and external scaffolds can provide suitable protection for truss-setting tasks. For example, bracket scaffolds placed on the inside or outside of a building provide large, stable walking and working areas for workers. To ensure safe use and appropriate load limits for bracket scaffold systems, workers should always follow the manufacturer’s instructions or consult a qualified person. For other requirements for scaffolds, refer to 29 CFR 1926 Subpart L, Scaffolds.
  • Ladders: For certain truss-setting jobs, platform and stepladders can provide a stable work platform for workers. They can be particularly helpful when set up inside a building. Workers should always use a ladder safely by following the requirements spelled out in 29 CFR 1926 Subpart X, Stairways and Ladders.
  • Spreader: An engineered spreader, when installed in accordance with the manufacturer’s instructions, distributes the force of a PFAS across multiple trusses. The roof trusses do not need to be sheathed to use a spreader. These engineered anchorage devices are reusable and can be uninstalled and reinstalled quickly. A qualified person should decide whether a spreader is suitable for use as an anchor.

 

After a Complete Truss Section is Fully Installed

Truss sections are multiple individual trusses (typically four) that are interconnected and fully sheathed. A truss section that has been restrained, braced and sheathed in accordance with the manufacturer’s instructions can be suitable as an anchor point for a PFAS.

Once the assembled truss section has been set and secured, it can be used as an attachment point for an anchorage device. From this point on, PFASs can be used to protect workers while they install additional trusses and roof sheathing.

Fixed anchors provide a secure point where workers can tie off their lifelines as part of a PFAS. Anchors for a PFAS must meet the 5,000-pound strength requirement or maintain a safety factor of at least two under the supervision of a qualified person—refer to 29 CFR 1926.502(d)(15).

Different types of anchors for these systems include, but are not limited to:

  • Peak anchors
  • Strap anchors
  • Bolt-on anchors

Once a group of trusses has been properly restrained and braced, a roof peak anchor can provide a usable tie-off point for a lifeline. Multiple peak anchors and lifelines can protect several workers. After confirmation from the manufacturer, some peak anchors may be strong enough to serve as tie-off points for two lifelines. Peak anchors can also be useful for fall protection during later roofing tasks or while setting another truss section.

 

Written Fall Protection Plans

If you do not use ladders, scaffolds or aerial lifts, and can demonstrate that it is not feasible or would create a greater hazard to use conventional fall protection equipment (guardrails, safety nets or PFAS) when working at heights of 6 feet or greater, you must develop a written site-specific fall protection plan in accord with 29 CFR 1926.502(k). The plan must be prepared by a qualified person as defined by 29 CFR 1926.32(m). This person could be the owner, the supervisor or a worker who has extensive knowledge, training and experience with fall protection and is able to solve problems relating to fall protection. States with OSHA-approved state plans may have additional requirements for written fall protection plans.

The site-specific fall protection plan must document at each location why the use of conventional fall protection equipment is not feasible or will create a greater hazard. The plan must also describe the alternative methods that you will use so that workers are protected from falls. Workers and their supervisors must be trained on the proper use of those other fall protection methods.

Conventional fall protection equipment can reduce or eliminate the chances of a fatal fall. Written site-specific fall protection plans ensure that protection continues, even when conventional fall protection methods are determined to not be feasible.

For more information on the requirements for a PFAS, refer to 29 CFR 1926.502(d).

Let me know you thoughts on fall protection and truss installation.  A good idea could save someone’s life.  Thanks.

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