Solution Summary: Ladder Leveler
A ladder leveler is an engineering control that may help improve ladder stability on uneven ground. A ladder leveler consists of two legs that are attached to the base of an extension ladder. The legs are independently adjustable to accommodate for uneven ground. Therefore, levelers provide stability and minimize fall risk. Falling from an extension ladder can lead to an injury, or even death.
Ladder levelers are attached to the legs of an extension ladder and allow the length of the legs to be independently adjusted. A leveler consist of two base units and two adjustable legs (one for each ladder leg). There are various makes and models, but most ladder levelers allow up to 8-1/2” adjustments. Most ladder levelers can be used on any width, height, load capacity, or material of extension ladder (aluminum or fiberglass). Some provide corrugated rubber feet or metal claws that can accommodate firm, wet, and/or penetrable surfaces.
To install, a base unit is secured to the original ladder leg by tightening wing bolts, screwing the base units into existing holes, or drilling new holes to secure the base unit. Once the base unit is secured, the adjustable leg is then locked into the base unit at any desired height (Figure 1). The adjustable leg is typically secured to the base unit by inserting locking pins or tightening wing bolts.
Figure 1. The Louisville Ladder Leveler
The Werner Equalizer is an extension ladder with built in adjustable legs that can be independently set in 3/8” increments up to 8-1/4” to accommodate for uneven ground. It is available in either aluminum or non-conductive fiberglass frames with heights of 20-, 24- or 28-feet that can withstand up to 250 lb.
The Werner Equalizer has dual channel holes and a steel locking pin to secure the desired level for each leg. To operate, the locking pin is removed to release the leg. Once, the leg is set to the desired height, the locking pin is replaced into the leg to secure it. Setting the legs can be done quickly which reduces time in stooped postures. The Werner Equalizer also features corrugated rubber feet or metal claws that can accommodate firm, wet, and/or penetrable surfaces (Figure 2).
Figure 2. The adjustable legs of the Werner Equalizer.
Platforms can also be used to level ladder legs (Figure 3). The PiViT® Ladder Tool is a 22 x 15.9 x 10 inch triangular platform that can be placed on uneven ground to provide an even surface to place an extension ladder. For instance, one end of the PiViT® can be placed on a step, and the other end can be rested on the step above, resulting in an even surface to place a ladder. The PiViT® is made from polypropylene, has a 500 lb duty rating, and includes non-slip surfaces to enhance stability.
Figure 3. The PiViT® Ladder Tool
Climbing extension ladders on uneven ground can increase the chance of a fall leading to an injury or even death. Fractures are the most common injuries associated with falling from a ladder, followed by strains, sprains, and abrasions. The leading cause of falls is from unwanted ladder movement during use. A ladder leveler can reduce unwanted ladder movement by accommodating to uneven ground and improving stability.
How Risks are Reduced:
Ladder levelers can reduce the likelihood of falls because the ladder legs can be adjusted for uneven ground. Additionally, levelers eliminate instability caused by placing objects under the feet of ladders to correct for uneven ground.
Research has shown that a ladder leveler is a current measure to control falls from ladders (Hsiao et al. 2008).
Manufacturers, vendors, and worksites claim that ladder levelers are effective at reducing instability due to uneven ground. Little Giant Ladders® states, “When the Little Giant Ladder has to be used on an uneven surface, the Leg Leveler offers a safe, stable solution.” Werner® claims, “[The EqualizerTM] …eliminates the unsafe practice of using bricks or blocks to make your ladder level.” Setting the desired leg height on the Werner EqualizerTM and ladder levelers may require less time in a stooped posture than searching for and placing various objects under the feet of a traditional ladder.
OSHA claims, “…if a ladder is not on a ‘level surface,’ it must be ‘secured to prevent accidental displacement.’ With respect to an adjustable leveler, in some instances, its use may be the equivalent of a ladder being placed on a level surface.” In addition, the Werner EqualizerTM meets both ANSI and OHSA standards.
Some ladder levelers can only be used with specific makes and/or models of extension ladders. Therefore, make sure the leveler will fit your ladder before purchasing. All ladders should be used according to the manufacturer’s instructions.
Setting the desired height of the legs requires a short duration in a stooped posture. However, placing various objects under the feet of a traditional ladder to accommodate uneven ground may cause more time in a stooped posture.
Refer to "Preventing Falls from Ladders in Construction: A Guide to Training Site Supervisors" for more information. http://www.cpwr.com/pdfs/HSPH_PreventingFallsFromLadders.pdf
Dan Anton, PT, PhD, ATC; and Kevin Wright, SPT – Eastern Washington University
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