It takes a lot of hands to safely install a new rooftop unit, as electrical connections are channeled into the unit while workers ensure that it does not move while on the hoist.

Safety is a priority when working on any mechanical equipment, but it is especially heightened when the equipment weighs several thousand pounds and is located on a roof. The setting described here is commonplace for commercial HVAC contractors. Some, like Griffiths Mechanical Contracting Inc. (Jonesville, Mich.) schedule days and weeks on the installation and service for one client alone.

“We are very busy right now,” said Griffith’s Jake Dykstra. “We have an upcoming job of installing 12 rooftop units on one building.”

Another Detroit-area contractor, Marble Mechanical Services (Birmingham, Mich.), services about 45 rooftop units for one local church-school complex. “Servicing these units is two weeks of solid work,” said Marble’s Brandon Wettlaufer.

Alan Porter of Flame Heating, Cooling, Plumbing & Electrical (Warren, Mich.) said that while the months of March and April are a little slow, rooftop service picks up dramatically in May. “I’ll service five rooftops on one job, which typically take about an hour a piece,” he said.

Servicing and installing multiple units - or just one - calls for a good understanding of the safety issues involved when working at elevated heights. Each of these Detroit-area contractors ensures that workers are trained and understand the dangers that are part of the job.


Marble’s Drew Wettlaufer said there are a few common sense safety issues to consider right away. “Make sure the power is off before doing any parts replacement,” he said. “When on the roof, make sure that you have a harness if you are close to the roof edge. And when rigging rooftop units, make sure all persons are away from the building area that you are lifting over.”

Flame’s Matthew Marsiglio added more tips. “Check accessibility to the roof and make sure there is enough area to work in,” he said. “Look for a safe guardrail if the unit is near the edge of the roof/structure and check for proper electrical lockout while the unit is under repair.”

Joe Zatek of Marble Mechanical Services inspects one of several rooftop units that he will work on in one day – making it even more important that he follow all safety rules related to working on each unit.

Safety goes beyond the techs and installers - it involves everyone at the jobsite according to Griffiths Mechanical’s Ryan Griffiths. “An overlooked safety issue is not always by the contractor, but from innocent pedestrians that may be shopping or working at the place where the RTU is being changed,” he said.

“You always have to barricade off the area around the crane or jobsite. We had people deliberately move and walk under the caution tape to get to their car at a Walmart project last year. You have to prepare for everything when lifting RTUs in public places.

“Another thing I always tell my guys is that the crane operator is not an automated robot, he is a human capable of error. If he makes one wrong move, it could cost you your life. You must always be alert when there are 2,500 pounds above your head!”

Servicing rooftop units is a lot safer when technicians pay close attention to safety training and use common sense.


Not only is safety important from a human standpoint, it is also important from an operational cost standpoint - namely insurance costs.

Wettlaufer said, “Our insurance and workers compensation can get expensive when guys are not working due to injury. Most building owners now want to see that you have a safety policy in place.”

Marsiglio said his insurance company is very proactive about safety training. “The majority of our safety training is done by either a representative from our insurance company or by utilizing videos supplied by our insurance company or vendors we purchase our safety equipment from,” he said.

Brad Wettlaufer of Marble Mechanical Services reveals the build-up of dirt and dust on the rooftop coil – a good reason for routine scheduled maintenance.

Other sources for these Detroit-area contractors include the Construction Association of Michigan and the Associated Builders and Contractors (ABC Central Michigan Chapter). Griffiths said, “All of our employees have been through our safety program we provide and all hold a full manual in their possession at all times for reference.”

Safety training is critical, but so is simple common sense. Richard Wirtz, HARDI technical director, summed it up: “You have to look at all things associated with the piece of equipment, i.e., operating pressures, refrigerants used, coil cleaning materials necessary, etc. Ensure that the service truck has a first aid kit and working fire extinguisher.

“Look twice and anticipate your next move. Your hands and feet must be in tune with your brain.”

Workers from Griffiths Mechanical Inc. watch as an old rooftop unit is being lifted off the roof of a shopping mall by a nearby crane.

Sidebar: Ladder Safety

The Occupational Safety & Health Administration (OSHA) publishes 10 basic rules for ladder safety. Marble Mechanical service tech Joe Zatek adds an eleventh: “Use the strap on the top of the ladder to attach it to a point on the roof.” He said, “On a windy day you might go back to your ladder and find it lying on the ground if it isn’t attached.”

1.Set ladders should be up at a 4:1 angle (1 foot out from the base for every 4 feet of rise).

2.Wear proper footwear with non-slip soles.

3.Face ladder while ascending and descending.

4.Don’t carry tools in hand; use a window cleaner’s tool belt, or belt designed for the ladder work to be accomplished.

5.Do not stand above highest “safe standing level” prescribed by ladder’s manufacturer, e.g., above top three rungs.

6.Do not extend the center of your body’s torso past either side rail of ladder, e.g., do not overreach.

7.Keep at least three points of contact when working, e.g., both feet and one hand.

8.When ladders are used to climb onto or off an upper surface, they must extend at least 3 feet above the surface.

9.Do not set up ladders in high-traffic areas.

10.Never leave an erected ladder unattended.

Publication date:06/13/2011