What is a tread in the context of stairways?

In the context of stairways, a tread refers specifically to the horizontal component that provides the surface for a person’s foot when ascending or descending the stairs. It is the part of the stair that individuals step on, making it a crucial component for safety and comfort when using the staircase. Each tread must be appropriately sized and constructed to ensure stability and to prevent slips or falls.

The other elements mentioned, such as vertical boards, framing, and railings, serve different purposes. The vertical board, known as a riser, supports the tread but does not serve as the surface where the foot is placed. The framing provides structural support for the entire staircase rather than being a part of the stepping surface. The railing is essential for safety by offering support and guidance, but it does not constitute a part of the stairway that is stepped on. Therefore, recognizing that the tread is the specific walking surface is important for understanding stair design and safety requirements.