Sending workers up on a roof comes with one big, obvious hazard. There are leading edges at every side and falling from any of them can result in a very serious injury.
In addition to those leading edges, you also have to worry about HVAC systems, roofs with multiple levels, skylights, roof hatches, and any number of potential trip hazards. Not to mention the risks associated with tools or materials falling off the roof to a lower level.
Given all these hazards, it's perhaps not surprising that it can be counted under 4 of OSHA's top 10 most frequently cited safety standards.
Employers are required to provide safety measures for all walking-working surfaces with an unprotected side, an edge that is 4 feet or more above a lower level, or any area within 6 feet from a roof edge. Depending on the particular features of the work environment, these measures can include guardrails, ladders with catches, gates, and fall protection harnesses.
In this article, we'll take a brief look at some important considerations for keeping workers safe when their job takes them onto a rooftop.
Securing the Perimeter: Installing Guardrail Systems
Railing systems will be a critical part of any roof safety program. The most common type you will see when protecting leading edges is a non-penetrating design using weighted bases, with a railing in that familiar safety yellow. The heavy base keeps these guardrails upright even when a worker loses their footing and falls against them. The non-penetrating design avoids the use of fasteners that could compromise the seal or integrity of the roof.
Guardrails can also be used around HVAC systems and skylights. In the latter case, however, it is preferable to also install skylight guards for an added layer of protection.
If there is a risk of objects falling off the edge, a toeboard is required on the safety railing. It must have a minimum of 3.5 inches in height and be able to withstand up to 50 pounds.
While guardrails are essential, there are numerous qualifying factors to specify before installing them. So it is vital to get the assistance of a qualified supervisor or contractor who can ensure that your system is both safe and compliant. Finding a qualified team that can provide installation services is also advisable.
You will also need additional planning if you are going to install a roof railing system on a historic building. Consult the preservation ordinances and factor in any criteria for the protection of historical property before loading up your equipment and bringing it to the site.
Another consideration is the roof's access points. If it has a hatch access, you will need an appropriate hatch railing with a self-closing gate. When purchasing products for these areas, you will generally be met with an extensive questionnaire designed to help you choose the proper application – take your time and fill out all the correct information to make sure you have the exact railing you need.
(Find out What the ANSI/ISEA 121-2018 Dropped Object Standard Means for Safety Managers)
Elevated roof sections and platforms require several areas of evaluation.
First, the platforms. To ensure proper fall protection from platforms or outdoor mezzanines with more than four steps, self-closing gates should be installed.
Next, look for any breaks in roof elevation of 19 inches or greater with no ramp. These breaks in elevation will require a fixed ladder at all points of access. Per OSHA 1917.118, these ladders must have slip-resistant surfaces, handrails, evenly spaced rungs, and must extend at least 42 inches above the top of the access level. Any fixed ladder more than 20 feet in height requires a cage or ladder safety device (although recent OSHA directives indicate that cages will be phased out by November 2036). If it is longer than 24 feet, a fall arrest system is required as part of the ladder.
(Learn more about Fall Protection and Ladders)
Slips and Trips
Another area to consider, per OSHA 1910.21-30, is whether there are any trip or slip hazards, such as cables, piping, standing water, loose gravel, or debris.
The first step is to following proper housekeeping procedures to minimize clutter and reduce the number of potential tripping or slipping points. If a slip or trip hazard can't be mitigated this way, you will need to install small ramps or platforms with steps and railings so workers can avoid the hazard.
Fall Protection Harnesses
Fall protection harnesses come under OSHA 1910.140 and must be worn and tied off on any walking-working surface that has an unprotected side or edge that is 6 feet or higher above a lower level.
These harnesses should be worn with harness attachment points on the back, at shoulder blade height. Per OSHA 1926.140, an anchorage point is required that is able to support 5,000 pounds per employee. The distance of freefall slack should be kept to a minimum, but no more than 6 feet in length.
This will require having multiple outdoor points throughout the roof, which can tempt some workers or supervisors to tie use guardrails as tie-off points. This shortcut must be avoided entirely, however, as these railings are not designed to provide sufficient support for a fall arrest system.
(Learn more in Fall Arrest Systems: Can You Tie Off at Your Feet?)
Stay Safe Up There
Roof safety is covered by multiple regulatory codes and there are countless of options to choose from to mitigate rooftop hazards. With so much to consider, it can quickly become overwhelming.
Well before you send someone up on a roof, it's recommended that you do your homework and employ a qualified contractor focused on total employee safety – from design through installation.
Remember, you're dealing with leading edges that could result in falls from high above the ground. There's no room for quick fixes and half measures. If you're going to do work on a roof, you have to do it safely and do it right.
Want to learn more? Check out our Fall Protection Knowledge Center.