Curved Cantilevered Staircase Design in Hempstead, NY

At Hempstead Floating Stairs , curved cantilevered staircases start from a full field survey of the space — because no two Nassau County homes have identical foyer geometry, ceiling height, or floor-to-floor dimensions.

A curved cantilevered stair is one of the most structurally complex residential stair types. The horizontal offset between the top and bottom landings, combined with the curve radius, determines whether a single-spine steel stringer is structurally viable or whether a twin-stringer or central support column is required. That decision has to be made from actual measurements, not from a client's description of the space or a rough floor plan. We take full dimensional field measurements before any design work begins.

The stringer for a curved system is fabricated from plate steel bent to the designed radius — not approximated with a series of straight sections welded together. Straight-segment approximations look acceptable on paper but create abrupt transitions in curvature that are visible in the finished stair and concentrate stress at the segment joints. Our shop bends continuous plate to the engineered radius, which produces a smooth geometric curve and distributes load evenly along the stringer length.

Winder treads on curved stairs are wider on the outside radius than the inside. The New York State Building Code requires that the tread depth be measured at a point 12 inches from the narrow end, and that minimum tread depth be maintained at the walk line — the center of the stair path. We detail every tread geometry to comply with these requirements and verify compliance for each step in the run, not just the average.

Wall connection for curved systems is more complex than a straight stair because the anchor points span a curved arc. We map anchor locations to coincide with framing elements — studs, blocking, or structural headers — so each anchor sets into solid material, not into drywall or cavity space. In Nassau County homes where the curved stair runs against an exterior wall, we also verify there's no insulation cavity directly behind the anchor zone that could affect embedment depth.

Fabrication time for curved systems is typically 6 to 8 weeks from engineering approval. The geometry requires more shop time than straight stringers, and the continuous-bend process has a slower cycle than straight cuts. We build that lead time into the project schedule from day one.