Ladder

A ladder is a rigid or hinged device used for climbing between different heights. It typically consists of two side rails connected by rungs or steps, forming a portable stair-like structure. Ladders can be used at inclined angles or in self-supporting configurations. Common types include step ladders, which are self-standing in an A-frame when opened; extension ladders, which consist of two or more sections that telescope to reach higher places; and multipurpose or combination ladders that can be converted into different forms. Attic ladders and library ladders are specialized variants.

Materials commonly used are wood, aluminum, and fiberglass. Wood ladders are traditional but heavier and can deteriorate; aluminum ladders are lightweight but conductive; fiberglass ladders provide non-conductive properties desirable for electrical work.

Key components include side rails, rungs or steps, feet with non-slip ends, and, in some designs, spreaders or locking mechanisms to stabilize the ladder. Safety features such as slip-resistant treads, rung locks, and stabilizing feet are often included.

Ladders are used in construction, maintenance, painting, firefighting, and many household tasks. Safety is a central concern; users should inspect ladders for damage, maintain three points of contact, avoid overreaching, and set up at the proper angle (roughly one unit of height for every four units of base). Conductive ladders should not be used near energized equipment or overhead power lines. Weight ratings and manufacturer guidelines should be observed.

Standards: Portable ladders are regulated in many regions by safety agencies and international standards such as EN 131 in Europe and ANSI/OSHA guidelines in the United States.