Ladders could well be one of mankind’s oldest inventions. The image of a ladder depicted in a Mesolithic rock painting in Spider Caves in Valencia, Spain dates back to at least 10,000 years ago. While ladders are indispensable in many forms of structures from prehistoric to modern times, they can also prove hazardous if not properly used and maintained.
Like all things, ladders come in various types to serve different purposes. They include stepladders, articulated ladders, extension ladders and combination ladders. To make sure that workers are not overreaching and putting themselves at risk of a nasty fall, the height at which a ladder is used and the load it supports must be considered.
According to ladder manufacturer Werner, headquartered in Greenville, Pennsylvania, the maximum safe reaching height is a little more than one metre above the height of a ladder, while an extension ladder should tower an additional two to three metres above the highest support point.
Portable ladders should be able to support at least four times the intended load which can escalate quickly, considering that materials such as a can of paint are often carried up ladders, the Occupational Safety and Health Administration (OSHA) in Washington, D.C. notes.
Ladders are commonly offered in three materials — fibreglass, aluminum and wood — and each comes with its own strengths and weaknesses. Employees who work with electricity or engage in any task where contact with electricity is a potential risk should use a wood or fibreglass ladder for its non-conductive properties, while a metal ladder can stand up to more wear and tear in heavy-duty work environments such as construction sites, information from Werner notes.
Different materials need to be cared for differently as well. The Canadian Centre for Occupational Health and Safety (CCOHS) in Hamilton, Ontario recommends that fibreglass ladders be cleaned and sprayed lightly with a clear lacquer or a paste wax every three months, while wooden models should be protected with a clear sealer or a wood preservative. Extension ladders should have their pulleys lubricated and any ropes that are frayed or worn must be replaced.
Having a clear work area is crucial before setting up a ladder, as a slippery surface or unstable base can cause the feet of a ladder to slide, the CCOHS notes. Ladders that lean against a wall must follow the one-to-four rule: the ladder’s feet must be away from the wall one-quarter the height to the top point of contact, and that top point of contact must be strong enough to support any weight exerted on it. Barricades also need to be set up around the ladder if it is used in high-traffic areas, WorkSafeBC notes.
For a tool that is used in just about every industry, it is also one that workers need to handle with caution. After checking that the ladder is secure, ensure that all locks are set before ascending an extension ladder. Three points of contact must be maintained at all times when climbing — two feet and a hand or two hands and a foot. Workers should only hold onto the rungs of the ladder and not the side rails. Tools should not be carried up a ladder, but hoisted or attached to a toolbelt, the IHSA notes.
Although a user’s weight or size typically does not contribute to the likelihood of a fall, improper climbing posture can create clumsiness that leads to falls. To reduce the chances of a fall, the American Ladder Institute recommends that users wear slip-resistant shoes, avoid sudden movements and keep the centre of the belt buckle between the ladder side rails when climbing to maintain balance. A worker’s weight, clothing, personal protective equipment and the weight of tools and supplies carried up a ladder should all be considered when calculating the weight on a ladder, the institute adds.
Ladders should be inspected after purchase, before each use and after every time they have been dropped, the CCOHS advises. The inspection should look out for the following:
• missing or loose steps or rungs;
• damaged or worn non-slip feet;
• loose nails, screws, bolts or nuts;
• corrosion, rust, oxidization and excessive wear, especially on treads;
• rough or splintered surfaces and sharp edges on rails and rungs; and
• twisting or distortion in the rails, as a twisted or bowed ladder is hazardous.
Fibreglass ladders need to be checked for exposed fibreglass or cracks and wooden ladders must be free from rot, decay or warped rails. Attention should also be paid to painted areas, which can hide defects in wooden ladders. Defective ladders should be repaired or replaced, the CCOHS advises.
The proper storage of a ladder is important in extending its life span and ensuring its proper function. Tall ladders should be hung horizontally on racks, with supports at every two metres to prevent the material from sagging, the CCOHS advises. If a ladder is mounted in a vehicle, it should be tied to the supports and padding should be used to reduce wear and tear from road shocks. Wooden ladders should also be kept in a dry and cool area.
Jean Lian is editor of OHS Canada.