Ladder jacks are devices that are often used as a means of establishing some type of scaffolding between two ladders. The idea is to create a temporary structure that is capable of supporting workers and equipment while completing some type of task, such as painting or whitewashing the exterior of a building. In design, a basic ladder jack is shaped like a triangle that is equipped with brackets, making it possible to attach the jack to rungs on the ladders involved.
When engaged properly, a ladder jack fits over the rungs of a ladder and extends in a horizontal fashion. Once in place, it is normally a good idea to test the positioning of the jack, ensuring that the fit is tight and that the device is not likely to slip out of place. Once a second jack is affixed to the second ladder, some type of scaffolding or planking can be placed on top of the set of jacks, creating what is usually called a ladder jack scaffold.
With this application, painters can quickly place two ladders into position and create scaffolding that is capable of holding their weight as they work. The benefit of this approach over simply climbing up a ladder is that there is more room for materials like paint and brushes to remain near at hand. In addition, the painter is able to move about more freely, covering a larger area that would be possible otherwise. When using a single ladder for the same task, the painter would have to periodically stop working, climb off the ladder, move it, and then climb up a second time in order to finish with that same amount of area.
In the past, a ladder jack was normally constructed using some type of heavy metal. Today it is possible to purchase aluminum ladder jacks rather than models made with steel or iron. There are a few models constructed with heavy-duty plastics, although these tend to be more limited in use than the metal versions.
While a ladder jack is capable of supporting an equitable amount of weight, they are somewhat limited in strength. Various sizes and brands of the device will normally specify a maximum amount of weight that can be placed on the scaffolding and still be considered safe. In addition, local regulations may require that anyone working with a ladder jack scaffolding also use some type of protective harness if the platform created with the use of the jacks is more than a certain distance from the ground.