Anytime one leaves the ground, the further above terra firma one goes, the more risk of injury or death that worker assumes. In China, scaffolding is still built of bamboo, held together by rope. At sea, the worker goes over the side of the vessel held only by a wood seat and a rope. In America, we have a slightly more sophisticated process, in that we use steel frames to support the weight and stress of multiple levels of workspace access. Scaffold systems of today aren’t much different from 100 years ago, and the data suggests that the accidents and injuries have only decreased slightly since then. Most of the danger presented by scaffolding is in the planking.
Currently, there are four major categories of plank recognized by the Scaffold, Staging, and Framing Institute. The most commonly used is solid sawn wood; one piece of lumber cut from appropriate timber, and always stamped by a certifying agency to verify its authenticity. The second is an engineered wood product known as laminated veneer lumber. These planks are constructed of layers of wood, glued together by adhesives, and often strengthened by wooden rods or dowels. The third category is metal. Used in heavy-duty applications, these planks can be aluminum or steel, galvanized or not. Although safe, these planks are heavy and require maintenance to protect them from rust and corrosion. The fourth category is the composite plank, comprised of fiberglass matting, encased in plastic for maintenance-free longevity.
DANGER ZONESEvery year in this country alone, there are more than 4,500 injuries from scaffolding, with almost 90 deaths every single year. Of the 2.3 million construction workers, 65 percent must access scaffolding to complete their functions in the field. The cost of these accidents is staggering. Last year, $90 million in days of lost work can be attributed to scaffolding injury. The medical bills, legal bills, temporary benefits, and permanent benefits costs for the injured are phenomenal.
According to the Bureau of Labor Statistics, 72 percent of the injured workers attribute their scaffold accident to planking giving way, plank slippage, or slipping on the plank by the worker. Anyway you slice it; the planks are the most dangerous part of the scaffold system.
The dangers surrounding scaffold planks are many. Accidents occur due to compromised plank being put into service when it should have been retired. Many planks in use today are planks that have been in service too long. These planks get damaged by the sun, they are rarely stored inside, or with adequate protection, but moisture is by far the biggest cause for premature deterioration. Wood planks absorb moisture, and dry out, hundreds of times in the life cycle of that plank. Every time a plank gets wet and dries out, it loses some of its natural oil and moisture, causing it to become more brittle. Wood plank stored outside in colder climates get snowed, or rained upon, causing the plank to absorb all that water. When temperatures dip below freezing, that water turns to ice and expands causing cracking and splitting of the plank. These cracks severely jeopardize the structural integrity of those wood planks, and can be invisible to human inspection. Ask a scaffold contractor when a wood plank is bad and he’ll tell you, “When you fall through it.” Also, these wood planks are irreparably damaged by being dropped on their ends during removal, from nailing and saw cuts from workers, and through misuse. Planks should never be used as truck ramps to get through mud, or for loading and unloading of heavy equipment. Proper storage techniques are rarely used, allowing scaffold planks to get fungus, termites, or dry rot.
Another common accident occurs when these planks slip off their respective frames. As workers and supplies make their way across the bays, these generally unsecured planks can move, causing the overlap on each end to move into a possibly unsupported position. Conversely, if a worker steps on the overlapping section at the end of the scaffold bays, again unsupported, tragedy is inevitable.
That brings us to another major hazard, the overlapping planks. When these planks are overlapped, the uneven surface seams like a magnet, grabbing every cord, hose, and rope that comes near it. Feet are no exception. Trip hazard is the third leading cause of scaffold injury. Trying to focus on production, while consumed by where to put one’s feet, is daunting at best.
SLIP AND SLIDEThe possibility of slipping is also a real concern of workers on scaffolding. These planks can get icy, wet, or splattered with any number of building products, including but not limited to, construction debris, cleaning agents, tool lubricants, and sand aggregate, making for a slick surface and looking for the unsuspecting.
Among the most heart-stopping dangers of scaffold planking is the often variable deflection from plank to plank. Deflection, or flexing under load, can vary greatly depending on age, grain, type of wood, type of composition, number of knots, and any other variable found in a natural product like wood. As a worker moves across the walkway, each board below his feet flexes differently. One board could flex 1/2 inch, while the board right next to it flexes 2½ inches. Anyone who has ever stepped on wood plank scaffold knows exactly what I’m talking about. You’ll think you’re going right through it. It is critical, due to these differing deflections, to step solely on one board at a time, hoping for the best. Stepping on two boards simultaneously will surely result in a twisted ankle, and possibly much worse. Loss of balance is one of the most fatal accidents that can occur on scaffolding.
Another hazard, experienced by the installer/remover is the shear weight of planking. A dry 12-foot plank averages about 42 pounds, while it could weigh as much as 62 pounds when wet. This makes for quite a risk when passing these planks up to the fourth and fifth level of the scaffold. All of these scaffold planks are installed over the head of the worker, risking injury from lifting, both on installation and take-down. Back injuries are right at the top of the list. Not only are they heavy, but their length causes greater strain as well. Unless the installer is quite strong, it may require two men.
Compared to these issues surrounding planking systems on scaffolding, slivers from the wood seem irrelevant. The bottom line in safety is the responsibility of each of us. We all need to keep an eye out for dangerous conditions. Each worker must not only be aware of his/her safety, but also the safety of others, who may not see the danger. Proper testing and certification, adherence to safe building practices, increased knowledge, and vigilant project management must never become complacent. Cutting corners on scaffolding and staging is like cutting one’s throat. Always insist on quality scaffolding. Don’t be afraid to ask to have damaged, old, or overly flexible boards replaced. If it doesn’t look right, ask your foreman, or project manager. If it still doesn’t look right, don’t go. It could be the mistake of a lifetime, or even the end of it.
Saving lives and reducing injuries will lead to reduced medical bills, loss of productivity and reduced legal action. The result: increased profitability. W&C