Problems
When laying brick or block, scaffolding is used to provide access to the face of the structure. When laying block toward the bottom of the scaffolding, the mason must flex the trunk to reach. Frequent and prolonged trunk flexion is associated with low back pain. When laying block above shoulder level, raising the arms is prevalent. This posture is associated with shoulder disorders. Also, when adjusting the scaffolding level, lifting heavy planks is required. This task requires bending and twisting, coupled with heavy, awkward loads — all risk factors for low back pain.1
Masons often need to stoop to pick up brick, block, and mortar and place them on a wall. This work can require a lot of bending and twisting of the body. 2
You have to bend deeper and twist your body more often if you keep materials below hip height, or lay brick or block on a section of wall below hip height. 2
Frequent stooping causes fatigue and puts stress on your lower back. This stress increases your chance of developing low back pain or serious back injury. Your risk of injury is even higher if you also twist your body quickly, especially when holding heavy objects.2
Solution — Adjustable Scaffolding
Use split-level adjustable scaffolding. This allows a brick or block mason to stoop less because the materials and work surface are both kept near waist height, which is more comfortable and stresses your body less. Split-level adjustable scaffolds are available for jobs ranging from small single-story residential work to large high-rise building projects. This equipment may not be appropriate for all jobs. 2
You can use adjustable scaffolding that provides for a continuous height adjustment. This adjustment allows the masons to lay block at about waist level, thus minimizing the awkward trunk postures associated with back pain. Furthermore, after the initial setup, the planks do not have to be moved, so the task of manually moving planks to adjust the scaffolding levels has been eliminated, as have the associated risk factors.1
How It Works
Adjustable scaffolding has separate platforms for the worker and the materials. Since the worker platform can be raised or lowered, the materials and the work surface can both be positioned around the height of the worker's waist. Small scaffolds can be raised manually using hand jacks or a hand winch. Taller scaffolds can be raised using a powered winch. 2
Benefits for the Worker and Employer
Masons reduce their chance of developing low back pain or back injury. Workers spend less time handling materials because brick, block, and mortar are moved shorter distances. Workers expend less physical effort and report less fatigue at the end of the day. They also appreciate the wider platforms, which give more room to move around. 2
Mason tenders who build conventional frame scaffolds also get important benefits. Split-level adjustable scaffolds reduce the heavy physical labor involved in continuously changing the height of a frame scaffold. There is less lifting and carrying of frames and heavy boards, and less moving materials to the ground and back. Split-level adjustable scaffolds also reduce the danger of falling that mason tenders face when building frame scaffolds. 2
Measurable increases in productivity have been reported when split-level adjustable scaffolds are used. One study found that masons' productivity increased 20% when using the scaffolds, and some contractors have reported even greater increases in productivity. 2
Results
After an average follow-up period of 399 days, one construction company that implemented adjustable scaffolding achieved the following results1:
• The CTD incidence rate remained at zero;
• The ROI for adjustable scaffolding is undeterminable at this time due to lack of measurable data;
• The turnover rate (per 200,000 hours worked) changed from 47.5 to 27.9 — a 41-percent improvement;
• The average risk factor score for three affected tasks in the company was 31.3 before the scaffolding was put into place, and was 30.3 afterward - a 3-percent improvement.
Approximate Cost
Costs vary depending upon how the work platform is raised (manual vs. powered), the height of the masonry wall, and the overall size of the project. Heavy-duty scaffolding for three-story commercial work runs about $300 per lineal foot. Light-duty scaffolding for residential and light commercial work of the same height runs about $200 per lineal foot. Contractors who have used these systems say that productivity increases allow them to recover the cost, but actual benefits will vary. 2
For More Information
- Products related to this solution are described at CPWR's Supplement to NIOSH's Simple Solutions
. - Local contractor tool and equipment suppliers or rental companies may be another source of information on products.
- For general information on this solution, check CPWR's Construction Solutions Database and eLCOSH - Electronic Library of Occupational Safety and Health.
Other Scaffolding Pages
Adjustable Mast Scaffolding
Adjustable Tower Scaffolding
PDF Downloads
Ergonomic Best Practices for the Construction Industry
Resources
1 Information in this section is drawn from "Ergonomics Best Practices for the Construction Industry" published by the Ohio Bureau of Workers' Compensation
2 Information on this page is drawn from "Simple Solutions: Ergonomics for Construction Workers" published by NIOSH
