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.

Jershon, Inc. Automatic Ladder Leveler

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 Automatic ladder leveler. (Photo courtesy of Jershon, Inc.)

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.

Werner Equalizer

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). 

PiViT® Ladder Tool

Platforms can also be used to level ladder legs. 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 pounds duty rating, and includes non-slip surfaces to enhance stability.

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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