A ladder is a portable set of rungs used for climbing to higher levels. It is one of the oldest tools in construction. The modern ladder is made of aluminum, fiberglass, or wood. Aluminum is light and strong but conducts electricity. Fiberglass is heavier but non-conductive, used near power lines. Wood is traditional but requires maintenance. The ladder is not just a tool. It is a safety device. Falls from ladders are a leading cause of construction injuries.

Ladders come in several types. A stepladder is self-supporting and has a hinged back. An extension ladder is adjustable in length and leans against a wall. A straight ladder is a single fixed length. A platform ladder has a standing platform at the top. A combination ladder converts between stepladder and extension configurations. Each has its own load rating, from Type III (200 pounds) to Type IAA (375 pounds). The rating must match the user and the tools.

Ladder safety is straightforward but often ignored. The ladder must be on level ground. It must be set at the correct angle, about 75 degrees for an extension ladder. The top must extend three feet above the landing. The user must face the ladder and maintain three points of contact. The ladder must not be overloaded. It must be inspected before each use. A cracked rail or a missing foot makes the ladder unsafe. The ladder is a simple tool. It can also be a deadly one.