Tread
A tread is the horizontal portion of a step in a staircase that serves as the primary walking surface for ascending or descending between levels. Typically constructed from durable materials such as wood, metal, stone, or concrete, the tread provides a flat, stable plane designed to support the weight of users while ensuring safety and comfort. Key dimensions of a tread include its depth, which determines foot placement, and the nosing, which is the front edge that often overhangs the riser to improve visibility and provide additional foot space. In architectural design, treads are critical for maintaining consistent proportions within a flight of stairs and may incorporate non-slip textures or decorative finishes to enhance both functionality and the overall aesthetic of the vertical circulation system.

