Which type of materials is NOT typically used for ladders?

Concrete is not typically used for ladder construction due to its inherent properties that do not lend themselves to the design and usability of ladders. Ladders need to be lightweight, portable, and easy to handle, allowing for quick setup and movement. Wood, aluminum, and fiberglass are materials commonly used for ladders because they meet these requirements effectively.

Wood is a traditional material that offers good strength and stability. Aluminum is favored for its lightweight nature and resistance to rust, making it ideal for both indoor and outdoor use. Fiberglass ladders are excellent for electrical work because they do not conduct electricity, adding an essential safety feature. In comparison, concrete is heavy, cumbersome, and impractical for ladder applications, which require users to easily climb and reposition the equipment. This makes concrete an unsuitable choice for ladder material.