Solution Summary: Roofing Lift Trailer
A roofing lift trailer is an engineering control that can reduce musculoskeletal disorders (MSDs) from manual material handling and stooped postures by assisting workers in moving down roofing debris during rooftop work. These trailers are hydraulic powered.
A roofing hydraulic trailer, such as the Equipter RB4000, has a container size measuring 104x64x29 inches that is 4.1 cubic yards. There is a 10 feet 6 inches wide catch area with the container lids open (figure 1). The RB4000 is powered by a 13-horsepower Honda engine which enables it to be self-propelled and lift the container 12 feet high with a 4,000 pounds jobsite lift capacity. The trailer towing capacity is 3,360 pounds.
Figure 1. Aerial view of the catch area for the RB4000 (Source: https://www.equipter.com/products/rb4000)
Workers performing roof work are subject to stooped postures and repetitive lifting and carrying during job site clean up. Stooped postures and heavy lifting can cause MSDs of the low back, such as muscle strain or a disc herniation (“slipped disc”), which is bulging of disc material possibly pressing on the spinal cord or nerves that go into the leg.
In addition, workers descending ladders while transporting roofing debris are at risk of falling from heights. While carrying roofing debris down a ladder, workers are not able to maintain three points of contact, which are needed to safely ascend and descend a ladder.
How Risks are Reduced:
The roofing lift trailer eliminates the need for workers to manual carry roofing debris down ladders. Since workers will be hands free while descending ladders, they spend less time in awkward and potentially dangerous postures. In addition, using the roofing lift trailer would reduce the risk of a fall as workers decrease the number of times they need to ascend the ladders to bring down roofing debris.
The roofing lift trailer reduces injury risks from repetitive lifting and carrying and stooped postures. Rather than sliding the old shingles down the roof and having them fall to the ground, the raised trailer could catch them at the roof's edge. There would not be much of a need to have the workers bend over to pick up the shingles that are strewn all over the ground like the current way roofers perform this task.
Safety and health experts believe a roofing lift trailer minimizes heavy lifting and carrying and therefore can reduce the incidence of MSDs. There have not been independent published studies measuring the effect of a roofing lift trailer on the incidence of low back disorders. However, studies have shown an association between manual materials handling and low back pain. (Kuiper et al. 1999; van der Molen et al. 2005). A roofing lift trailer reduces the amount of manual materials handling during clean up and therefore may reduce the incidence of low back pain.
Although there are no published studies on low back injuries and roofing lift trailers, safety and health experts believe there is a reduction in risk. Lifting with the back bent forward increases the risk of low back injury (Hoogerdoorn et al. 2000). A roofing lift trailer reduces the need for workers being in stooped postures during clean up.
Effects on Productivity:
There is an improvement in productivity when using as the manufacturer states the RB4000 "improves... efficiency and maintains a much cleaner jobsite" thereby reducing clean up times. It has been reported that approximately 75% of RB4000 owners complete at least two more jobs per month.
As the RB4000 is a self-propelled equipment, operators should be cautious of other workers and bystanders to avoid struck-by incidents. As such, universal alarms may be installed to provide warning while equipment is in use.
It is recommended users follow all manufacturer guidelines before using this equipment to ensure worker safety and compliance with applicable local, state or federal regulations.
Jean Christophe Le, MPH - CPWR The Center for Construction Research and Training