When Is a Warning Line Sufficient Fall Protection for Roofing Work?

In 2021, according to data from the U.S. Bureau of Labor Statistics, there were 951 fatal work injuries in construction and extraction occupations—370 of those were from falls, slips or trips. In the same year, there were 123 roofing industry fatalities, with 99 of those resulting from falls, slips or trips.  

The National Roofing Contractors Association has partnered with OSHA since 2014 to host the annual National Safety Stand-Down to Prevent Falls in Construction weeklong event to raise safety awareness to prevent fall injuries and fatalities. 

As part of this year’s free webinar series in May, speakers addressed a variety of safety topics for roofers, including the value of and standards for using warning-line systems. 

“Small contractors make up a huge section of the roofing industry,” said Rich Trewyn, NRCA’s director of enterprise risk management and the main speaker of the warning-line webinar. Trewyn also included an infographic from the Center for Protection of Workers’ Rights and the National Institute for Occupational Safety and Health that showed 91% of construction companies have fewer than 20 employees. But those companies account for a whopping 75% of fatal falls.  

"The impact of falls for small contractors is huge,” Trewyn said. “Before we even get out there, we need to make sure the surface has been prepped and reviewed to ensure nothing will catch our workers by surprise when they are on the job." 

Trewyn said there is an express mandate from OSHA to have fall protection for construction employees working on the roof. Between October 2021 and September 2022, the most frequent citation by OSHA was related to fall protection.  

Trewyn illustrated that this protection should include (among other things): 

Fall protection: devices and myths 

There are a variety of conventional fall protection devices, according to Trewyn, including guardrails, safety nets and personal fall arrest (PFA) systems. However, he wanted to stress the importance and value of warning-line systems to low-slope roofing work (4:12 or less). On such projects, conventional fall protection devices can be combined with a warning-line system to keep workers safe.  

In this context, said Trewyn (quoting OSHA guidelines), “roofing work means 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.” 

He went on to explain OSHA’s definition of a warning line: “A barrier erected on a roof to warn workers they are approaching an unprotected roof side or edge.” They contain an area in which roofing work may take place without fall protection systems.  

"There are a wide variety of myths and misconceptions out there about when you can and can't use warning-line systems,” Trewyn said. Some of those mentioned include that roofers cannot use them anymore, any trade can use warning lines or a safety monitor, flags are not necessary, cones can be used as stanchions and more.  

To help dispel these myths, here are eight criteria from OSHA that Trewyn outlined to keep in mind when utilizing warning-line systems on low-slope roofing work.