Cantilever Stair
Staircase with treads projecting freely from the wall.
In a cantilever stair, each tread is fixed to the wall on one side only and cantilevers freely into the room on the other. Modern cantilever treads are secured to the wall or to a stiffened stringer with anchors. In timber or natural stone, each tread contains a concealed steel core onto which the tread is slid. Such constructions require a structural engineer's report or technical approval.