Ladders are devices that workers use to step up or gain access to elevated surfaces. There are several basic types of ladders, including rope ladders and rigid ladders. Rigid ladders can be step ladders, extension ladders, telescoping ladders, roof ladders, and hook ladders. Extension ladders are divided into two or more lengths for convenient storage and transportation, and so that the ladder can be lengthened for use. A pulley system can allow the ladder can be easily extended by an operator on the ground. Rolling ladders are mounted on wheels or casters so that workers can easily move the ladders into place. Marine ladders and dock ladders are made from materials that can resist corrosion, such as stainless steel or anodized aluminum.
Ladders made of wood are less expensive but heavier than ladders made of light-weight metal materials. Aluminum ladders weigh less but conduct electricity. Fiberglass ladders are suitable for working near wires because they are good electrical insulators. Options include number of steps, depth of steps, climbing angle, and slip resistance of the treads. Options for ladders include a standoff or stay at the top of a ladder to hold it away from the wall. Platform ladders include a platform or tray for holding tools or materials. Load rating is measured in pounds. An important consideration for selecting a ladder is the duty rating, which ranges from Type 1AA (375 lbs.) for extra heavy-duty industrial use to Type 3 (200 lbs.) for light-duty commercial use.