Be Your Plank’s Best Friend
When you take care of your planks, you take care of your workers, too
By Tom Inglesby
The rules are pretty clear: Scaffolding plank safety requires inspection and care. Several organizations have published “controlling” documents, including OSHA Safety and Health Standards and the Scaffolding Industry Association (SIA), with the most binding being those from OSHA. Sort through the legalese and technical jargon, and you’re left with simple, common sense things to consider on the jobsite and in the yard.
Inspection is critical, and both OSHA and SIA say an inspection must be done by a qualified person meaning “one who, by possession of a recognized degree, certificate or professional standing or by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work or the project.” Most contractors have at least one such person on staff – whether it’s the owner, a long-time supervisor, or someone who has been sent for specialized training in safety issues.
Although the rules call for a qualified person to perform inspections, the reality of life on the job indicates that anyone who steps a foot on a scaffolding plank must know enough to say if the rig is safe. For these daily ad hoc inspections, the worker can use guidelines and common sense equally well. Several companies that manufacture scaffolding planks produce detailed guidelines for selecting the right planks and simple, but complete, guides for field care and inspection.
McCausey Lumber Co. in Roseville, Mich., and Kennison Forest Products, in Sulphur, La., are examples of companies with guidelines available to clients and non-clients. Like you, these companies are concerned about job safety and the proper use – and avoidance of misuse – of their products.
“First, the contractor should buy from a reputable supplier of quality scaffold plank,” Jared Kennison, executive VP and general manager of Kennison Forest Products. “This ensures they meet all applicable standards. Second, all planks should be inspected routinely for damage and wear, so that they can be replaced as quickly as necessary. Correct storage and inspection are the keys to keeping good plank on the job.”
Interpreting what you see can be aided by illustrations, such as those in Kennison’s handouts, but it takes experience to make the right call each time. In most cases, it’s best to make the conservative call. “When in doubt, kick it out.”
As OSHA reports, wood ages and reacts to usage and will begin to show checks, splits and notches. These will vary in degree, depending on the loads a plank has carried, the weather to which it has been exposed, the length of time it has been in use, etc. Planks with splits – that is, cracks that go completely through the wood – for more than a few inches should not remain in service, as they may no longer maintain the necessary load-bearing capacity.
Planks with checks – cracks that are on the surface only and do not go completely through the wood – should be watched, as the checks may develop into splits over time. Sometimes, the contractor literally will notch a section of the board with a saw, perhaps so the plank can fit around a portion of a scaffold assembly. Notched plank can lead to problems since, essentially, a potion of the plank is now missing, thereby weakening the plank at that particular area.
OSHA says that scaffold planks that have accumulated layers of mortar, grout, paint, plaster, etc., are not permitted to remain in service, since it is impossible to determine their conditions. Dangerous splits may be hidden underneath those coatings.
If a scaffold plank has been used as a mudsill, it should not be returned to service on a platform. Moisture from standing water as well as point-loading from the scaffold legs may have weakened it, making it unable to bear the weight that will be placed on it.
The flex or “give” of a plank can indicate its condition. OSHA calls for deflection criteria of L/60 (the length of span in inches divided by 60) to get the maximum deflection limit at center span in inches. An example would be a seven-foot (84-inch) span between scaffold frame supports: 84/60 = 1.40 inches. Therefore, you’d never want to allow a plank to deflect more than 1-3/8 inches at the middle of that length span, regardless of type of plank being used.
Laminated plank has come into fashion because it can be made out of any tree. In addition, aluminum and even fiberglass “planks” have been tried. In the end, most contractors come back to wood, and most lumber companies stick with the best grades available in making their planks, whether solid sawn or LVL. Stamped with the necessary proof marks indicating they meet the OSHA and/or SIA standard, wood planks will serve for a long time if properly cared for in the field and when returned to storage.
Colby Hubler, managing director, Mill Direct Lumber in Tualatin, Ore., is chairman of the SIA Plank and Platform Council. He notes, “The SIA handbooks provide valuable information for storage and handling of scaffold planks. All wood planks, solid sawn or LVL, should be stored above ground on dunnage to keep moisture from entering the bottom of the units. Additionally, all units should have some sort of lath or stickers between layers to allow for air circulation through the unit.
He continues, “Most important, a tarp or something as simple as a sheet of plywood should be placed over the top of the unit to prevent moisture from dropping down through the unit. Ideally, indoor storage is best. Planks perform best when on frames, where air can work around them and keep them performing to their designed ability; not when flat packed and sitting in mud or water in the yard.”
Obviously, planks should be used only for their intended purpose. Any other use compromises safety and inhibits performance. Consider your safety the next time you are walking on scaffold planks. You are supported by them, and they deserve care to keep you alive and working.
Mark it DownThe Scaffold Industry Association Plank and Platform Council has produced pocket guides for the inspection and identification of scaffold planks. These are great tools for the field and provide an indispensible value. Visit www.scaffold.org.
About the Author
Tom Inglesby is a San Diego-based freelance writer whose work has appeared in numerous online and print publications. He is the winner of the Construction Writers Association's 2002 Boger Award for Special Reports.