What are the top and bottom surfaces of a trussed ladder known as?

The top and bottom surfaces of a trussed ladder are referred to as the "rail." These rails are the structural components that provide support and stability to the ladder. They run the length of the ladder, forming its long sides and serving as the main framework around which the ladder is constructed. This design allows for the distribution of weight and helps to maintain the ladder's rigidity when in use.

In the context of ladder construction, the terms "rung" and "end" refer to different parts of a ladder. Rungs are the horizontal steps that you stand on, while the ends may refer to the vertical components that connect the rails at their terminal points. The term "beam," while related to structural elements, does not specifically denote the top and bottom surfaces of a trussed ladder. Understanding the terminology is crucial for proper communication and safety in ladder use and maintenance.