Spiral staircases

Spiral staircases work best where floor space is limited or where a single design element needs to carry visual weight, such as in entryways, open-concept lofts, decks, and tight interior stairwells.

A straight staircase typically needs about ten feet of linear run to climb a single story. A spiral design completes the same rise in a five- to six-foot diameter footprint, which is why it’s the ideal solution for lofts, decks, and additions where a long hallway isn’t available.

Ordering a spiral staircase kit comes down to two measurements: floor-to-floor height and well opening diameter.

Floor-to-floor height is measured from finished floor to finished floor. The base of the staircase is straightforward to measure, but the top requires more measurement than the ceiling height. If your well opening is already cut, measure to the top of that opening, including the finished floor. If it hasn’t been cut yet, account for the depth of your rafters, the subfloor (typically 3/4″ plywood), and the thickness of whatever finish material you’re installing, whether that’s wood, tile, or carpet.

The well opening is measured as a finished dimension. For a standard, square through-the-floor installation, it should be 2″ larger overall than the diameter of the stair you’re installing, factoring in any trim, drywall, or other finishing that will line the opening.

Yes, spiral staircases are just as safe as straight staircases. Iron Shop stairs are fabricated with full penetration welds, high quality materials, and hardware. We offer code-compliant designs and provide downloadable engineered drawings if required by your local building inspector.

For households with small children or pets, we recommend options like non-skid tread options, in-between spindles, stair gates, and lighting kits.

Material, diameter, tread covering, finish, and whether the circular stair needs to meet code as a primary means of egress all factor into price. Because every staircase is configured to your space rather than pulled from a fixed catalog, the clearest way to see an estimated price is to Request A Quote with your measurements and design choices.

Staircase frames are available in steel and aluminum. Stair parts, like tread coverings, landing coverings, handrails, and more come in a variety of wood finishes including American Cherry, Baltic Birch, Hickory, Mahogany, Maple, Red Oak, Walnut, and White Oak. Composite tread coverings are also available. For a full list of available materials and parts, explore our Stair Parts catalog.

Configuration choices like tread depth, riser height, guardrail spacing, and handrail height, are all bound by code minimums. We build every configuration to meet these numbers, or beyond them where your local jurisdiction requires more. For a full list of code requirements, visit the Installation Library.

Most series can move outdoors with a change in finish and the base material. Aluminum is the standard choice near coastal or high-moisture environments. Carpenter spiral staircase kits are built for interior use only.

The American Industrial, Victorian, and Multi-Line Spiral series are all inspired by different eras. American Industrial features detail from the American Industrial Revolution which prized utility and strength, while the Victorian series carries ornamental scrollwork and detailed cutwork from its namesake period. The Multi-line Spiral series is influenced by the clean lines, simple forms, and functionality of Mid-Century Modern Design. The Carpenter series is built entirely from red oak, a rustic and traditional counterpoint to all metal collections while the Half Turn series is characterized by a 180-degree turn instead of the full circular motion of standard spiral stairs.