Stair tread

A stair tread is the horizontal part of a step where a person walks. It can be made of materials like wood, metal, or plastic, and in homes, it may be covered with carpeting. Non-slip treads are often used in commercial or industrial settings.

Stair treads come in various styles. Mid-flight treads include straight or flier treads for straight stairs, diminishing fliers that narrow before a turn to adjust handrail pitch, winder treads wider at one end for turning flights, and kite winders with quadrilateral shapes used in corners. Feature or starting treads are decorative, such as curtail treads that follow a spiral handrail curve, bullnose treads with rounded front edges, D-end treads shaped like a "D," tower features for newel posts, and commode fronts with curved edges.

USAB and ADA compliance require stair treads to have uniform depths of at least 11 inches (280 mm) and slopes no steeper than 1:48. Surfaces must be firm, stable, and slip-resistant.

Notable examples include Dylan's Candy Bar's staircase with candy-embedded resin treads, the "Piano Staircase" in China with alternating black and white treads, Seoul's underground musical stairs that light up and play notes, IDEO Labs' interns' musical staircase, and Johns Hopkins University's piano staircase playing the C scale.