Up on the Green Roof


Growing industry presents new safety challenges

The potential for falls is one of the biggest hazards associated with installing and maintaining green roofs. Dennis’ Seven Dees Landscaping, which has worked on this green roof project and others, is strict about safety requirements for its workers.

Green roofs are growing in popularity in cities throughout the country, and more landscape contractors are bidding on green roof projects. However, a review of numerous articles and Web sites on green roofs reveals little or no mention of safety issues.

“Don’t let the money that might be made in this new venture take your eye off of protecting your employees. There are new challenges, hazards and safety issues related to green roofs,” advises Fay Feeney, a certified safety professional and principal of the California-based Envision Strategic Group, a nationwide safety consulting firm.

Feeney, an active member of the American Society of Safety Engineers, adds: “Do a risk assessment analysis for each project. Identify the potential hazards, then offer the best solutions for mitigating those hazards.”

Green Roofs for Healthy Cities’ annual survey of corporate members’ completed green roof projects in 2006 showed a growth rate of more than 25 percent over 2005; this represents 3 million-plus square feet of green roofs installed last year. The growth rate for intensive green roofs that typically incorporate larger plants was 110 percent. Chicago, closely followed by Washington, D.C., installed the most square feet of green roofs, according to the survey.

Green roofs, which cover a building’s roof with plants, involve the use of technologies that incorporate drainage/filtering systems, quality waterproofing, root repellency and engineered growing media, Green Roofs for Healthy Cities explains. Among the benefits cited by the organization are a reduction in storm water runoff, better heat and sound insulation, energy savings, improved air quality, increased green space and a reduction in the urban “heat island” (defined by U.S. EPA as “urban and suburban temperatures that are 2 to 1 degrees Fahrenheit (1 to 6 degrees Celsius) hotter than nearby rural areas.”).

What about safety?

Despite all of the positives associated with green roofs, safety issues are clearly present. One of the biggest hazards is the potential for falls, according to both Feeney and Mark Barbour, a production manager at Dennis’ Seven Dees Landscaping, Inc. in Portland, Ore. A second major safety issue, the two agree, is how the landscape contractor will get the materials up to the roof.

“We are installing our fifth green roof and have two more coming up. My biggest concern is the fall—you have to have that (safety) harness,” Barbour says. Getting too close to the edge of the roof, even with a guardrail, is also a major concern, he says.

“My next concern is getting the materials up there. Most of the time, the tower crane has already come down; sometimes, we have to go up the elevator. If you use the crane, you have to shut down access to the site. You can’t really shut it down, but for safety reasons, you have to monitor it. We’re at a site on the waterfront in Portland now, and I have two guys standing there being spotters,” Barbour says.

Other safety issues, he adds, include wearing the appropriate clothing and personal protective equipment, such as boots, hard hats and safety glasses.

More and more landscape companies are installing and maintaining green roofs. This is one of a number of green roof projects Dennis’ Seven Dees Landscaping has become involved in.

Feeney, who notes that there are many safety-related issues that should be evaluated before installing a green roof, believes that the following are the top three:

• Has the architect (both the building architect and the landscape contractor) anticipated guardrails that will protect from the fall hazard? Note: Make sure that your bid also takes into account the necessary OSHA-required fall arrest systems that will need to be in place.

• How will the materials be brought up to the roof? Will there be an elevator to a staircase? Is there enough manpower to get the materials up safely?

• Are you certain that the work area can support the materials, mechanical equipment and the weight of the people? If necessary, meet with the structural engineer, she suggests.

Feeney cites the following as other important safety issues to consider during green roof installation:

1. The basics about employees and material handling.

Plan out the logistics. Review OSHA’s standards. Check to see whether the building or the roof specifically has an area for employee hand washing, restrooms and breaks from potential heat stress. Is there a planned shade area?

2. Planning for emergencies.

How will any injured employees be taken off the roof and be provided with appropriate medical care?

3. Communication.

Will the project manager have communication with building management or the contractor who is on site at all times? For example, she says, if a pipe breaks when putting in a watering system, the water will need to be turned off so it doesn’t result in roof failure.

“The big issues are that you have to get staff up there; it is pretty isolated when you are up there, and if anything goes wrong, you’re at higher risk than you are at ground level,” Feeney says.

OSHA Concerns

Federal OSHA officials in Washington, D.C., note that most of the same hazards associated with the installation of conventional roofing materials are present with the installation of green roofs. Landscape contractors installing green roofs must comply with OSHA’s construction standards. The ongoing maintenance of a green roof falls under federal OSHA’s general industry standards.

“Of course, fall protection would be an issue. Cranes would also be involved, so OSHA’s crane standards would be applicable. Powered industrial trucks (forklifts) may also be involved in staging the materials on the ground,” a spokeswoman for federal OSHA says.

Keep in mind that 24 states, plus Puerto Rico and the Virgin Islands, have state-run OSHA programs with standards that are often even stricter than federal OSHA regulations. It is important that you know whether the green roof project you are involved in falls under federal or a state-specific OSHA plan.

Barbara Mulhern is a Belleville, Wis.-based agricultural/horticultural freelance writer.

Green Roof Risk Assessment

Fay Feeney, principal of Envision Strategy Group, recommends using this process to determine the hazards present to employees involved in the installation or maintenance of green roofs.

Problem Identification and Analysis
1) Identify and analyze hazards.
2) Assess Risks.

Consider These Actions in Order of Effectiveness
1) Eliminate hazards and risks through system design and redesign.
2) Reduce risks by substituting less hazardous methods or materials.
3) Incorporate safety devices.
4) Provide warning systems.
5) Apply administrative controls (e.g., work methods, training).
6) Provide personal protective equipment.

Make Decisions and Take Action Measure for Effectiveness
1) Reanalyze as needed.

Reduce Your Risk of a Fall

Use this brief tailgate safety training lesson to train employees who work on green roofs to protect themselves from falls.

• Falling from a roof can result in instant death.

• Be on the constant lookout for hazards that could result in a fall.

• Common hazards: getting too close to the edge of the roof, tripping on an uneven surface or falling through a hole or other opening.

• Always use the protective equipment we provide, including personal fall arrest systems.

• Keep a safe distance from guardrails.

• Do not overreach.

• Walk, don’t run, whether on the roof or on the ground.

• Keep your mind on your job. Don’t engage in horseplay or become distracted.

• Promptly report any unsafe conditions by a co-worker to your crew leader or another supervisor.


Federal OSHA has some Web-based materials available to assist both you and your employees who will be installing or maintaining green roofs:

• General fall protection

• Construction fall protection

• OSHA Construction e-Tool (available in English or Spanish, this e-tool includes accident photos showing falls from elevation and other materials you can use to train your workers)

• Cranes

• Forklifts

• OSHA Quick Cards (many of these brief training cards are also available in Spanish)