You might situate your spiral staircase in your home’s foyer, or in a downstairs living room, open hallway, multi-level garage, or another suitable area. Before you get started on your project, consult your local building codes and see what criteria they contain about spiral staircases. In some cases, building codes might dictate that staircases satisfy specific spatial dimensions, including width. [2] X Research source
If one or both floors are carpeted, be sure to start your measurement from the underlying solid flooring rather than the top of the carpet, as this is the surface you’ll be building on. [4] X Research source
Plan on adding at least 2 inches (5. 1 cm) to the chosen diameter of your staircase to ensure adequate finger clearance along the outer handrail. [5] X Research source Your spiral staircase may need to be a certain minimum width if it’s to serve as the main stairway for your home. For more information on stairway diameters or other safety considerations, consult your local building inspector or talk to a qualified contractor. [6] X Expert Source Andrew PetersArchitecture & Construction Specialist Expert Interview. 24 November 2020.
Remember that building codes (and therefore minimum required tread depths) may differ from place to place. To avoid costly errors, it’s always a good idea to check before you build. Unlike ordinary stair treads, the treads on a spiral staircase taper on the interior edge where they attach to the central support column.
For a planned staircase that’s going to be 96 inches (240 cm) high, you would divide 96 by 7 to get 13. 71, or 14 steps. You would then divide 96 by 14 to conclude that each step should be placed 6. 85 inches (17. 4 cm) apart. Each step of your staircase also needs to offer a minimum of 6 ft (1. 8 m), 6 in (15 cm) of headroom in order to meet national building codes.
Double-check your plans to confirm that they’re as complete and precise as possible. Making a mistake in the planning phase could end up costing you time and money once you actually begin building.
Modular kits come complete with everything that you need to put your staircase together, along with full, detailed instructions to guide you through the assembly process from beginning to end. Modular spiral staircase kits can range in price from as low as $1,000 to $100,000 or more.
If you’re installing your staircase in an area with carpet, hardwood, tile, or laminate flooring, you’ll need to remove the flooring materials in order to expose and mark the subfloor underneath. Anchoring the center column of your staircase directly to the subfloor will help ensure maximum stability.
All-wood staircases may be constructed around a wooden post rather than a metal pipe. If you opted for a modular spiral staircase kit, it will include a center column that’s been prefabricated to a length that matches the specifications of your home. [13] X Research source
If you haven’t already, pull up the flooring material in your work area to gain access to the subfloor. Alternatively, you can purchase a premade steel base plate sized to fit your center column. These typically have slots for screws or bolts molded right into them. In order to guarantee that your center column will support the weight of both the completed staircase and its future occupants, it’s important that you secure it directly to a floor joist or undamaged section of concrete subflooring. [15] X Research source
It’s a good idea to pick up 2-3 extra blanks in case you make a mistake while cutting your first couple treads. If you plan on building an all-wood staircase, you’ll also be responsible for cutting your own stringers, balusters, handrails, and optional risers, all of which will require extensive woodworking expertise. [17] X Research source
There are many companies that manufacture premade treads designed specifically for spiral staircases. If you’re working with a modular staircase kit, it should come with premade treads, tread covers, and spacers.
Fasten wooden treads by cutting a neck into the narrow end and screwing or bolting them to the center column. Depending on the style, you might anchor the wider ends to the outer stair stringer, as well. Most premade metal treads are designed to be slid over the center column and tightened down. Some kits include alternating spacers to eliminate the guesswork involved in getting every step exactly the same distance apart. [20] X Research source
Unless you’re skilled in metalworking and have access to specialized machinery, you’ll probably find it easiest to just purchase a handrail or have one made to your precise specifications. Another common option for fabricating wooden handrails is to cut short curved sections from multiple pieces of wood. [22] X Research source
Check to make sure all of your balusters are secure. A loose baluster is an accident waiting to happen! Balusters are a functional touch as well as a decorative one—they enclose the sides of the staircase, which helps to prevent falls and other mishaps.
