Solution Summary: Sloped Roof Slide Guard-Guardrail System
A sloped roof slide guard-guardrail system is an engineering control that can prevent falls to lower levels from sloped roofs during residential construction. Guardrails are the primary means of fall prevention in construction, providing a physical barrier that prevents people from falling to lower levels. A typical guardrail consists of a top rail at a height of 42 inches (+ 3 inches) above the walking/working level, a midrail at a height of 21 inches above the walking/working level, and a 4-inch toeboard.
This specialized guardrail system consists of adjustable bases that attach to the roof 8 feet apart and can accommodate seven different roof slopes, including 6:12 (27°), 8:12 (34°), 10:12 (40°), 12:12 (45°), 15:12 (51°), 18:12 (56°), and 24:12 (63°, also known as A-frame). These bases have U-channels (figure 1) to accommodate 2-by-6 boards to serve as slide guards for construction workers to brace on.
Figure 1. Roof slide guard-guardrail base.
Each base also has a vertical rail pocket (figure 1) to accommodate metal tubing post with brackets that support 2-by-4 cross members that serve as top-rails and mid-rails. Extensive NIOSH testing showed this design supports more than twice OSHA’s top-rail strength requirement of 200 pounds when anchored with 16d nails (Bobick and McKenzie, 2011). When screw fasteners were used, the system supported more than three times the OSHA requirement (Bobick et al, 2015; pending publication in June 2015).
Falls from height can cause serious injury and death. Properly installed guardrails can prevent worker injury or death from falls by providing a physical barrier. This passive method of fall prevention is preferable to fall arrest systems because it prevents a worker from taking a fall and, once installed, requires no additional action from the worker. A guardrail can help reduce injury or death by preventing falls from heights.
How Risks are Reduced:
When constructed correctly, guardrails can prevent a person from falling from heights. Guardrails provide a physical barrier between the person and the fall hazard.
Safety and health experts, as well as manufacturers and vendors, firmly believe there is a fall risk reduction when guardrails are erected and installed correctly. A guardrail is termed a "fall prevention method," which means it prevents a worker from falling from a height. This method is preferred over other types of fall protection such as personal fall arrest systems and safety nets, which are systems that arrest the falls once it happened. When these methods are employed, the worker experiences a fall and is caught by the safety equipment. On the other hand, guardrails effectively eliminate the fall hazard when installed correctly.
Effects on Productivity:
There is limited peer-reviewed evidence on the effects on productivity of guardails as fall protection solutions.
The roof slide guard-guardrail system was designed for durability maintaining its functionality for re-use over multiple building seasons.
Roof brackets can be installed in conjunction with roof slide guard-guardrail system to serve as level working and walking planks (figure 2).
Figure 2. Roofing brackets shown in blue.
The Protector being sold by Reese Wholesale is a patented design developed by NIOSH. In addition, there are three other variations to the sloped-roof design to which the bases (flat base, vertical base, and vertical offset base) can also accommodate unprotected interior edges and stair cases primarily in residential construction.
For more information, please visit guardrails in Construction Solutions.
OSHA 1926.502(b) provides safety and health regulations for construction pertaining to guardrail systems.
On December 16, 2010, the Occupational Safety and Health Administration (OSHA) issued a new Directive (STD 03-11-002) that rescinded the interim fall protection standards (STD 3.1 and STD 03-00-001) that had been in effect since 1995 and 1999. The rescission eliminated the use of slide guards as the “sole means” of achieving an approved fall protection plan. Although OSHA did not eliminate the use of slide guards, the agency wants them to be used in conjunction with the requirements of Subpart M of 29 CFR 1926. Thus, the slide guard-guardrail system developed by NIOSH addresses this rescission by providing an option to accommodate an OSHA-compliant guardrail system.
Center of Gravity
If a worker's center of gravity is above the top rail, he or she should stay back at least 6 feet from the guardrail. An alternative is to extend the guardrail upwards. Guardrails can be extended to 45 inches high.
A recent innovation in railings, which is typically seen in atrium style hotels, places an addition to the top rail positioned outward and upward 10 to 12 inches and at a slope of 30 to 35 degrees from vertical.
Installing guardrails can be a dangerous activity. While the worker or workers are installing the guardrail there is typically no fall protection against the fall hazard until the guardrail installation is completed. It is best to pre-plan and engineer anchorage points for the installation workers to tie off restraint systems or personal fall arrest systems while the guardrails are being installed.
Le, Jean Christophe, MPH - CPWR - The Center for Construction for Research and Training
To obtain information, visit Protector Guardrails or contact 1-317-202-8200
Guardian Fall Protection Residential Guardrail System
To obtain information, visit Residential Guardrail System or contact 1-800-466-6385
Fall Protection Equipment
Fall protection equipment for residential construction classified by the type of equipment and the phase of construction can be found on this Washington University website. http://www.ot.wustl.edu/fptech/homepage.htm