Solar safety

Working with rooftop photovoltaic systems presents fall-protection compliance issues

Recent technological advances, improved aesthetics and valuable government incentive programs for photovoltaic (PV) roof systems have expanded their feasibility to a wider variety of building types. If you install or are considering installing PV systems, you may find yourself challenged during the job-hazard analysis project phase to determine Occupational Safety and Health Administration (OSHA) fall-protection rules applicable to PV roof system installations.

In some cases, available fall-protection controls you rely on may not be applicable to PV system installations. The nature of the installation and the material used may dictate how you protect your workers from fall hazards.

Fall-protection overview

Fall protection in the U.S. roofing industry is required under federal OSHA jurisdiction by the provisions found in 29 CFR 1926.500-503, Subpart M. However, though most OSHA state-plan states have incorporated these federal fall-protection regulations and their specific fall-protection control systems into their rules for worker protection, some state-plan states such as Arizona, California, Kentucky, Michigan, North Carolina, Oregon and Washington have unique fall-protection requirements that differ significantly from federal rules. In some states, broader fall-protection system options for workers are available to select based on the nature of the work and hazards faced.

OSHA construction regulations apply to work performed in a contract for construction, alteration or repair. Construction workers generally are required to use fall protection when they are exposed to a potential fall distance of 6 feet or greater. OSHA's general industry rules address most workers in manufacturing, warehousing and other business classifications and mandate fall protection when workers are exposed to fall hazards of 4 feet or greater.

Generally, roofing workers on slopes less than 4:12 must be protected from falls at heights 6 feet or greater by guardrail, safety net or personal fall-arrest systems—often called conventional fall protection. Conventional fall-protection systems also are required to protect other workers addressed in the construction regulations.

However, OSHA rules applicable to roofing work on low-slope roofs also allow a warning-line system in combination with one of the conventional fall-protection systems or a warning-line and safety-monitoring system be used to protect workers from falls. On roofs 50-feet wide or less, a safety-monitoring system alone may be used.

A critical factor when using fall-protection systems not considered conventional under OSHA rules is the work being performed must fall within OSHA's "roofing work" definition. OSHA defines roofing work as the "hoisting, storage, application, and removal of roofing materials and equipment, including related insulation, sheet metal, and vapor barrier work, but not including the construction of the roof deck."

If work being performed on a low-slope roof system does not fall within the roofing work definition, only conventional fall protection may be used to protect workers at heights 6 feet or greater. On slopes greater than 4:12, only conventional fall protection may be used to protect workers without regard to whether the work being performed meets the roofing work definition.

However, on some residential steep-slope buildings, other fall-protection measures may be employed under the auspices of a written fall-protection plan if you show conventional fall protection is infeasible or creates a greater hazard. There is a presumption conventional fall protection is feasible and will not create a greater hazard and, accordingly, you have the burden of establishing the controls provided in a fall-protection plan are appropriate.

PV fall protection

OSHA's roofing work definition will be paramount when properly analyzing which fall-protection control systems may be used to protect workers during PV system installations. Because the definition references the application of roofing materials, OSHA is likely to consider roof-integrated PV system installations roofing work because the material being installed comprises the weatherproofing membrane along with the PV component, or the PV components are adhered directly to the roof membrane.

But OSHA is less likely to consider rack-mounted PV arrays or panels installed on a weatherproofing membrane's surface as roofing material because they do not serve a weatherproofing function. OSHA clearly considers the installation of flashings on frames for rack-mounted PV system components, conduits or other PV element penetrations roofing work.

Similar distinctions apply to repair and maintenance work related to PV components. If the work involves a roof membrane's integrity, OSHA more likely will characterize it as roofing work. OSHA is likely to view repair or maintenance to PV components in racks or panels, structural or framing elements, raceways or conduits, or junction or combiner boxes that have no effect on a roof membrane's integrity as outside the scope of the roofing work definition.

In a vast majority of instances, the practical result of this distinction will be work involving roof-integrated solar components because they comprise the actual roof membrane or weatherproofing component, more clearly falling within the roofing work definition, allowing the use of warning-line and safety-monitoring systems. Direct work on other rooftop PV components, unless performed to ensure weatherproofing of an underlying roof system, will require one of the conventional forms of fall protection under OSHA rules because OSHA will not consider the PV components roofing materials.

The 15-foot rule

An exception created by OSHA often is referred to as the 15-foot rule. Under this rule, announced by OSHA in a letter of interpretation in May 2000, OSHA says certain physical barriers not meeting the strength requirements for guardrails, such as warning lines, may be used to contain a work area and will be considered adequate fall protection if the following four elements are present:

  • The warning-line setup is at least 15 feet from a roof edge or a hole.
  • The warning line meets the criteria in OSHA's regulations for warning-line strength and setup.
  • No work is allowed to take place outside contiguous work areas created by warning lines.
  • The employer effectively implements a work rule prohibiting workers from going outside the warning line (that is, closer to the roof edge or hole).

This exception allows for the performance of a number of repair and/or maintenance activities related to PV systems and other rooftop activities performed by a variety of construction trades without other forms of fall protection.

Personal fall-arrest issues

Of the conventional fall-protection options under OSHA's rules, personal fall-arrest setup and use may present some challenges, especially for steep-slope building designs with certain PV system installations. Lifelines, whether rope-grab or self-retracting, can present problems if PV system components impede deployment of the personal fall-arrest system.

For example, if a PV rack's structural framing pinched a self-retracting lifeline cable and restricted its retracting motion before a worker's fall or if additional lifeline had to be played out to access areas, this could result in potential increased free-fall distances.

Some resources designed to ensure firefighters' safety when accessing roofs with PV systems in place during fire emergencies have the additional benefit of assisting roofing contractors with fall-protection system selection during PV system installations and repairs. The Solar Photovoltaic Installation Guideline developed by the California Department of Forestry and Fire Protection, Office of the State Fire Marshall in April 2008 sets out nonmandatory guidelines for access areas and pathways for PV system installations on roofs.

The guidelines are valuable because they provide clear roof perimeters at distances from low-slope roof edges that allow effective warning-line system setups with a sufficient work area to perform necessary tasks while remaining inside the warning line. For steep-slope applications, access paths and perimeter guidelines also are established for hip and gable roofs, which allow for more free movement of personal fall-arrest lifelines.

Stay safe

Roofing work involving PV systems can be accomplished under current OSHA regulatory requirements and fall-protection options. However, such work presents some issues that you must meet to ensure fall-protection options are compliant. Understanding the specifics of OSHA's Subpart M will help keep workers safe and PV system installations trouble-free.

Harry Dietz is NRCA's director of risk management.



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