Scaffolds are common equipment and are used to allow workers to safely access and work at areas at heights. But if you build scaffolds incorrectly or use the wrong materials, these structures can be unsafe.
Three roofing workers in Massachusetts unfortunately learned this lesson the hard way. They were hospitalized after a two-story fall from a scaffold platform that broke beneath them. Their injuries included spinal, eye, facial, chest and rib fractures, a punctured lung and other broken bones.
OHSA inspectors concluded that the incident happened because a spruce plank used as the platform couldn’t support the workers’ weight and wasn’t graded for scaffold use. In fact, the invoice for the plank was clearly marked “not for scaffold use.” As a result, the company was fined a total of $294,500 for various violations.
That’s why the scaffold requirements in the OHS regulations often specify exactly what kind of wood can be used in wood scaffolds.
For example, in BC, all lumber used to construct a scaffold must be graded and marked to the National Lumber Grades Authority Standard Grading Rules for Canadian Lumber [Sec. 13.16 of the OHS Regulation]. And the OHS regulations in Nova Scotia state that if sawn lumber is used for scaffold planks, an employer must ensure that it meets one of the following specifications:
The planks are No. 1 grade or Select Structural Spruce-Pine-Fir (S-P-F) grade and sized 51 mm thick and 254 mm wide; or
The planks are No. 2 grade or better and sized no smaller than 38 mm thick and 235 mm wide rough sawn lumber, and are doubled up and fastened one on top of the other [Sec. 23.10(2)].