Which Spiral Stair Kits Is Best for You?

wooden spiral staircase with beautiful curved railing
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Spiral stairs are space efficient. They connect one floor to another using the smallest possible footprint. So especially if you have a smaller living space, you might find value in a spiral staircase. This article will inspire you with some of the possibilities installing a spiral stair kit can provide, from maximizing space, to facilitating storage, to creating a design centerpiece.

Circular Stairways vs Traditional Stairways

Traditional stairways typically require a minimum of 13 to 15 steps to climb an 8-foot wall, taking up a minimum space of over 8-feet (2,438 mm). This increases if the stairway has a landing changing its direction.

Spiral stairways only occupy as much space as their outside diameter, which can be as small as 42-inches (1067 mm) or even less. This space is the same no matter how many risers a spiral staircase has, which gives you a high degree of control over how steep each step should be, as well as the angles of entrances and exits.

Spiral Stairs vs Helical Stairs

Before going further, there is a misunderstanding that should be addressed about circular stairs, which has to do with their structural designs. Any stairs built with a curve or winding steps are either spiral or helical, but both are often generally referred to as spiral stairways, even though they can be built with many structural differences.

Spiral Stairs

Spiral stairs are circular forming a complete circle to the diameter of the staircase, with all of its treads radiating about the central point of the circle as we climb or descend the steps creating a spiral design.

With a uniform and equal tread depth, and their handrails contouring their outside perimeter, the domestic stairway with an outside diameter between 56 to 80-inches (1,400-2,000 mm) can be as wide as 80-inches (2,000 mm), or even more in commercial buildings.

The key difference is that the narrow inside end of each of the stair treads all originate from the center point of the circle, where they’re all supported by a central column.

Helical Stairs

Often referred to as “curved stairs,” helical stairs can be made in several shapes, going from a circle to an oval shape, or even an elliptical configuration.

But even in their simplest circular form, the helical stairs have a void at their center (or at the center point of their radius) making them much larger in physical size for the same tread width as a spiral staircase.

The helical stairs, however, are much easier to ascend as the stair treads aren’t as narrow at their inside end as with the spiral stairs.

small cabin space with metal spiral staircase

Spiral Stair Functionality

In terms of efficiency and lesser floor space, the spiral stairs take the lead on both counts.

They do lack a leisurely pitch—their steeper incline, feeling somewhat like a ladder, tends to make the climb feel tight and more difficult, especially while carrying larger objects up and down.

But they leave you with much more room, upstairs as well as downstairs, also providing the possibility of more light and can be made a great center point of the room with a little creativity on your part.

There are, however, certain basic restrictions that must be respected in regard to spiral staircases such as the width of the treads which must not be shorter than 26-inches (660 mm), with the depth of each tread no less than 7½-inch (190 mm) at 12-inches (305 MM) from the tip of its narrow end, and the rise never exceeding 9½-inches (240 mm).

At the minimum tread width and the maximum rise between the treads, the stairs will feel steeper and more like a ladder to climb up and go down.

Before building or especially prior to purchasing spiral stairs, you should take the time to check with your local building department to get an update on the current local codes for staircases. A shortlist of the regular and most standard restrictions normally used are as follows:

1. ) A minimum clear walking path of 26-inches (660 mm) creating an overall minimum diameter of the stairwell of 5-feet (1,525 mm).

2. ) A minimum tread depth of 7½-inches (190 mm) measured at 12-inches (305 mm) from the narrower end (or from the column).

3. ) The height of the rise from the top of any one of the treads to the top of the next tread up should never exceed 9½-inches (240 mm).

4. ) A minimum headroom height of 6½-feet or 78-inches (1982 mm) should be maintained throughout the staircase.

5. ) A curved handrail must be placed along the outside perimeter of the stairwell circle and run all the way throughout the staircase, at no less than 34-inches from the top of any nosing or as high as 38-inches.

6. ) The spindles between the handrail and the stair treads should be spaced close enough so that a child’s head can absolutely not fit through it, the maximum acceptable clearance being at 4-feet 3/8-inches (112 mm)—you should check with your local building code.

Figuring the Rotation and the Angle of Access at Both Ends

spiral staircase in room with table, chairs, and tree

As you begin planning your staircase, the first thing to decide is the location of the completed unit in the house and how it will affect the rooms at both floor levels.

You must decide at this point the direction of its rotation, either clockwise or counterclockwise, since it will affect the entry and exit points by at least 2-½ feet to the left or to the right at both floor levels.

Technically, the direction of its rotation, either clockwise or counterclockwise, will usually be determined by the hand that you reach out with to grab the handrail as you approach the stairs from the bottom to start walking up.

So as you get to the staircase, if you reach out with your left hand to grab the handrail to start climbing the stairs, you have a “Left-Hand Up” clockwise rotation, which will consequently become “Right-Hand Up” if you’re going to reach with your right hand for a counterclockwise rotation.

Construction of a Spiral Staircase

Spiral staircases are manufactured in several materials including steel, aluminum, wood, glass, and combinations of those materials. Whether you plan to install a staircase kit inside your house or outside on your deck or patio, you can be sure that there is a spiral staircase out there to fit your needs.

For outdoor use, for instance, the structural materials used to fabricate it will be galvanized steel or aluminum with stair treads possibly from grated steel for colder areas where there are chances of snow and ice, or from embossed or plain steel for warmer climates.

Your staircase can also be coated with any color of your choice.

Some companies might choose to specialize in manufacturing stairs in limited materials such as steel, aluminum, wood, or glass, but many are producing a wider range selection of those materials to offer their customers a greater varied selection in structural conception, treads, balusters, railings, and a range of other options.

A steel structure, for instance, can be complemented with a specially selected exotic specie of hardwood for its treads, railings, and other accessories, or perhaps by adding forged ironwork to a steel staircase to give it some specific historic style.

The range of options that can be offered with some of those stairs can be extensive considering that hardwood stairs come in red oak, ash, maple, birch, cherry, mahogany, walnut, or other species.

Metal staircases come in steel, galvanized steel, aluminum, and forged iron, processed in a variety of finishes from hot-dipped galvanized, epoxy, to custom color coating with the treads in plain flat or embossed steel, steel grating, hardwood, rubber, or plywood.

More and more companies can even offer 3/4-inch tempered glass treads with low-voltage lighting illuminating the frosted glass treads.

Wooden staircase designs make a great choice for any home as they can provide you with a great variety of styles and options that can be customized to the unique ambiance of your home, from a more traditional approach to a simple contemporary or modern look, it never fails to bring a warmer feeling to your home with its rich, unique, and varied wood grain patterns along with its variety of colors.

Wooden stairs usually make the focal point of the room it’s installed in and will undeniably influence your choices in decorating your home.

A forged iron spiral staircase can also offer a beautiful architectural structure to your room, indoors or outdoors.

Forged iron can be molded into all sorts of different shapes and attractive designs which makes it the ideal choice for complementing the decor of your home. A 12 gauge steel construction complemented with a richly designed forged iron railing coated with a black, red-oxide, or powder coat will make it a sturdy choice with a modern look and will provide you with a long-lasting beautiful option, inside or out.

A glass staircase will always remain a primary choice to create a truly classic style in a room, with its sleek and minimal lines.

Glass also blends smoothly with other materials and various styles, making it easy to combine with such materials as wood or metal. For instance, spiral glass staircases are more often constructed with glass treads connected to a steel column at its center.

You’ll also find that glass can also easily harmonize with wood or steel to provide a beautiful contemporary railing complemented with a stylishly molded handrail made from your favorite exotic wood coated with a rich finish.

But used on their own, solid glass stairs will provide your home with a spacious feel as the light passes through it, especially during daytime. The tempered glass will not deteriorate over time and can be made trapezium, curved, or even fitted to the adjacent walls.

Glass staircases can also be accommodated with low-voltage lighting to provide an illuminated 3/4-inch frosted tempered glass treads, but also comes with different textures of glass including clear, frosted, and sandblasted glass to accommodate most tastes.

Ordering Your Spiral Staircase

metal spiral staircase in brick room

The big advantage of buying your spiral staircase as a kit is that it leaves you with many more options of where you can place it in the house as opposed to the usual locations where you were usually limited by access to the lower and upper levels as well as on the main floor.

This also leaves you with more options for its size and for its angles of accessibility into both of the rooms at the different floor levels of the house.

One of the downsides you cannot neglect to consider, however, is that the spiral stairs can feel tight or restrained while going up or down the stairs, and impossible to meet someone coming from the other direction unless you get one with a very large diameter, costing you the practicality of the spiral.

By the same restriction, large pieces of furniture or other large objects will be more difficult to bring through to another floor, unless you’re provided with alternate access to that floor.

Note - Make sure that the direction of the spiral stair’s rotation is clearly specified as “Right-Hand Up” or “Left-Hand Up” when ordering, as it would dramatically affect the outcome of your project.

The staircase manufacturers fabricate their spiral stair kits in a wide variety of sizes, but it should be noted that a stairs diameter of any less than 5-feet (1524 mm), even though they’re made available, is not recommended, as they offer limited width constricting its accessibility to ascend but especially when descending its steeper angle.

Spiral staircases are also fabricated in either knock-down kits or complete one-piece units for delivery at your house. A one-piece unit will understandably offer more solid and durable construction and save you a lot of time in installation thus labor cost, while the knock-down option will save you a marginal amount in shipping fees.

Another fact that might be worth checking on the order’s layout sheet is the “angle of rotation of each step”. With the entry point at the bottom and the exit point at the top determined, if the exit point of your staircase exceeds the entry point by an extra number of degrees (rotation greater than 360°), this will affect the angle of rotation of each step of the staircase.

The angle of rotation of a step is the angle at which each tread rotates about its central column.

By dividing the total overall height from the bottom floor surface to the top floor by the riser height of each step, you’ll find the number of steps needed for your staircase.

Since the result will not likely give an even number, you’ll then have to adjust the true riser height to obtain an even number of steps. Narrowing the risers will give an extra tread making the climb smoother while widening the risers will make for a steeper staircase.

The staircase’s full rotation angle finally divided by the number of treads in your staircase will give you the “angle of rotation” of each step that is required to attain that full rotation from entry to exit.

Last but not least, always design the spiral staircase according to your area’s building code. With these tips and acquired knowledge, you can now plan your staircase and find out even more info on closely related subjects on specific types of staircases or how to integrate a spiral staircase into your house by following these links.