Roof parapets are a common design feature on many rooftops. However, there is a common misconception that the presence of parapets equates to an absence of fall hazards. But that simply is not always the case.
If constructed according to OSHA regulations, parapet guardrails can provide roof edge fall protection for workers. However, if they do not meet specific height & strength conditions put forth by OSHA 1910.29(b), they can not be considered guardrail. Furthermore, insufficient parapets can provide your workers with a false sense of security and potentially expose your organization to OSHA citation.
A parapet is a wall or raised edge extending above the roofline, often designed for weatherproofing, aesthetics, fire separation, drainage control, or other architectural purposes. To determine if your roof’s parapet can legally be considered guardrail, let’s discuss OSHA’s guardrail specifications:
The top edge height of top rails are 42 inches (+/- 3 inches) above the walking working surface. OSHA 1910.29(b)(1)
Midrails are installed midway between the top edge of the guardrail and the walking working surface. OSHA 1910.29(b)(2)(i)
Guardrail heights can exceed 45 inches as long as the vertical distance between midrails is no greater than 21 inches. OSHA 1910.29(b)(1)
Top rails and midrails are at least 0.25 inches in diameter or in thickness. OSHA 1910.29(b)(9)
Guardrail systems are capable of withstanding, without failure, a force of at least 200 pounds applied in a downward or outward direction within 2 inches of the top edge, at any point along the top rail. OSHA 1910.29(b)(3)
When the 200-pound test load is applied in a downward direction, the top rail of the guardrail system must not deflect to a height of less than 39 inches above the walking-working surface. OSHA 1910.29(b)(4)
Midrails are capable of withstanding, without failure, a force of at least 150 pounds applied in any downward or outward direction at any point along the intermediate member. OSHA 1910.29(b)(5)
Well, it really depends on how tall your roof’s parapet stands above the walking working surface. If the parapet is too short (under 39 inches) but structurally sound, a parapet-mounted guardrail can raise the effective barrier height to the OSHA guardrail range.
If the existing parapet is under 21 inches, the parapet-mounted guardrail must include a midrail. There is no limit to how many midrails are allowed on guardrails, but OSHA specifically requires the distance between any two midrails or a midrail and a top rail to not exceed 21 inches. However, additional midrails on guardrail systems can provide workers with the means to “climb” the guardrail, which is an illegal practice and extremely unsafe.
If the parapet is at least 39” tall, it could potentially comply with OSHA’s height requirements, but the building owner or employer must confirm that the parapet meets OSHA’s strength requirements as well. Both factors must adhere to OSHA regulations; otherwise, the system is noncompliant.
On rooftops where existing parapets meet OSHA guardrail height requirements but lack the structural integrity to withstand the strength requirements, the simplest remedy would be to add a free-standing guardrail system in front of the parapet. This would provide workers with a passive fall protection solution that is compliant with OSHA regulations and extremely effective at preventing falls.
Our Safety Configurator tool allows you to configure a customized guardrail solution for your rooftop – try it out today at www.safetyconfigurator.com
While we have mainly discussed guardrail as the solution to rooftop fall hazards, the truth is that OSHA regulations deem passive systems (guardrail) and active systems (fall arrest equipment) as equally compliant. However, as we’ve discussed in previous blog posts, not all fall protection solutions are equally effective in preventing injuries or fatalities.
The most effective way to prevent injuries is to prevent the fall from occurring, and parapets or guardrail systems are an excellent way to accomplish that goal. If we can prevent falls, we can prevent tragedies and save lives.
When your organization is ready to take the next step and ensure workers return home safely every day, we are here and ready to help.