A cantilevered floating stair in white oak and structural steel. Twenty-two treads with no visible support. Each tread 2.25 inches thick, 48 inches wide.
The engineering for a cantilevered stair at this span requires a structural steel spine concealed within the wall — a construction sequence that had to be coordinated with the framing crew months before the stair was built. Most builders have not done it. Most stair builders have.
The finish work took three weeks after installation — scribing the treads to the wall, achieving the 1/16-inch shadow gap the architect specified, and applying a hand-rubbed oil finish that will deepen over decades.