Helical Stair — Layout variation
Category: Layout variation
Curved staircase with an open stairwell opening.
The helical stair is a curved staircase whose flight winds around an open inner space – the stairwell opening. Unlike the spiral stair, there is no central load-bearing column; loads are carried by curved outer stringers and, if required, by an inner beam. The plan can be round, oval or polygonal. Notable construction variants include the helical stair with a central curved inner stringer into which the treads are set, and the helical stair with cantilevered treads, where only fine balusters stabilise the outer tread edge. Helical stairs are structurally demanding: the curved stringers are typically produced by bent or block lamination, and the tread flaring calls for precise calculation or specialised stair design software. They are widely regarded as a particularly representative stair form and often become the dominant design element of a room.
Related terms
Related terms: Spiral Stair, Curved Staircase with Stairwell Opening, Harp Stair, Walking Line, Winder Tread, Wreath Piece.