Metal Stair Stringers – Styles and Construction

Learn About Metal Stair Stringers – Designs, and Construction

Floating stairs with metal stringers are on trend for all types of interior and exterior design of residential and commercial projects. Since staircases are frequently situated at the entrance of the home they are the first thing that guests notice upon entering and they set the tone for the design of the home. Therefore, stair stringer style and construction should be considered an integral part of your stair design decision. Keuka Studios is the perfect choice for architects and homeowners looking to choose the specific elements of their floating stairs, to suit their desired design aesthetic. We create unique and innovative designs of floating metal stairs. Allowing you to pair a variety of metal stringer styles with a wide selection of railings and tread styles to accommodate the space requirements and achieve the desired finished look.

What are the types of metal stair stringer construction?

Stair stringers can be constructed in a variety of styles including round tube, square tube, rectangular tube, I-beam, c-channel, cantilever, zig-zag, sawtooth, hollow form, and double stringer. Each stringer design style can add a modern, refined, rustic, or industrial appeal to the space.

Metal Stair Stringer Styles

There is a wide selection of stair stringer types available and several examples of our completed projects are shown below. Click on the pictures to view the completed projects in our gallery.

1) Rectangular Tube Single Stringer Stairs

Custom-designed and fabricated grand entry single-stringer split staircase with a rectangular tube stringer and laser-cut tread supports. The Keuka Style curved cable railing system is surface mounted on the treads and fascia mounted on the catwalk.

Rectangular Tube Mono Stringer with Laser Cut Tread Supports
Rectangular tube mono stringer with laser cut supports
Grand entry double staircase made with rectangular tube mono stringer and wood treads.
Grand single stringer stair made with rectangular tube stringer

2) Round Tube Curved Floating Stair

Open-concept great room with a gently curving floating mono-stringer stair positioned in the center entrance of the home. The stair gracefully transcends up to the second-story open balcony. The stair stringer is made of a round tube, with round handrails and our Ithaca-style cable railing.

Illustration of round tube stair stringer showing tread supports.
Round tube stringer
Curved round tube stair stringer with cable railing and wood steps shown in a homes great room entrance.
Curved floating stair with round tube stringer

3) Zig-Zag Double Stair Stringer

A zig-zag stringer staircase adds a modern and open touch to the home. The staircase is made with laser-cut steel stringers in a zig-zag style. Each stair tread perfectly aligns with the horizontal lines of the stringer. The stainless steel cable railing system posts are surface mounted to the treads and landings.

Illustration of double stringer laser cut in the zig zag style.
Double zig-zag stair stringer
Double zig zag metal floating stairs with stainless steel cable railings.
Modern Stairs with Zig Zag Stringer

4) Square Tube Mono Stringer Floating Stair

Designed to have a modern simplistic aesthetic this staircase blends a floating stair stringer with a closed stringer staircase The staircase is fabricated with a square tube single stringer and a framed glass railing with wood treads and waterfall handrails.

Illustration of square tube mono stringer stair with tube tread supports.
Square tube mono stringer with tube tread supports
Floating stairs with square tube stringer and wood treads, with a glass raiing.
Floating square mono-stringer stair with glass railing

5) Exposed Cantilevered Stair Stringer

The offset mono-stringer stair is made of steel and has cantilevered tread supports engineered to support stone treads. The unique cable railings system posts are tapered and attached to the steel stair tread supports below the stone treads.

Illustration of rectangular tube mono stringer cantilevered.
Rectangular tube cantilevered mono stringer
Cantilever exterior stairs with stringer along concrete wall and stone steps with cable railing.
Floating cantilevered mono-stringer exterior stair

6) Double Rectangular Tube Stair Stringers

Interior floating staircase with open risers and double rectangular tube-style stringers. Paired with our Ithaca-style cable railing system the stairs have an elegant and sophisticated aesthetic. The railing posts slice through jatoba treads and attach to the tread support.

Illustration of a double stringer stair with in the rectangular style.
Double rectangular tube stringer
Double metal stringer stair with rectangular tube stringers and wood treads with cable railings.
Floating staircase with double stringer

7) Concealed Cantilevered Stair Stringer

The stringer for this cantilevered staircase is hidden within the structure of the wall creating a clean minimalist appearance. The metal tread supports extend out from the wall and is concealed by the wood treads. Also, the cable railing posts are designed to slice through the wood treads and connect to the tread supports.

Illustration of cantilevered stair with the stringer hidden in the wall and the tread supports cantilevered from the main stringer.
Hidden stringer with cantilevered tread supports
Cantilevered stair with stringer hidden in stone wall, wood treads and a cable railing
Cantilevered stairs with concealed stringer

8) C-Channel Double Stair Stringers

Chosen for a party barndominum is this c-channel stringer since it perfectly complements the desired rustic industrial style of the space. The Ithaca-style cable railings are mounted to the stair stringer. This railing style is used throughout the interior and exterior.

Illustration of C-channel double stringer stairs.
C-channel stringers
c channel double stair stringer with rustic aesthetic
Double C-channel stair stringers

9) I-Beam Stair Stringers

Located in an industrial setting is this monumental staircase with I-Beam stringers. The cable railing is our Ithaca style made to a height of 42 inches with an ADA-compliant handrail. The railing system is powder-coated steel with an aluminum top rail.

Illustration of double stair stringer with I-beam construction.
I-Beam Stringer
I-Beam stringer stairs with cable railings in industrial building.
Monumental double stringer I-beam stair

10) Square Tube Mono Stringer with Blade Tread Supports

Interior designers for an office space remodel decided on a rustic style with wood treads for their floating stair project. The Square tube steel mono stringer has blade tread supports and is finished in a bare metal clear matte to achieve this industrial appearance.

Illustration of square tube mMono stringer with blade tread supports
Square tube mono stringer with blade tread supports
Rustic mono stringer floating stair with blade tread supports and rustic wood treads.
Mono stringer stair with blade tread supports

11) Hollow Form Floating Mono Stringer Stair

Floating mono stringer stair made with hollow form construction. This stringer approach allows for sharp corners on the edges and more freedom of shape in design. This staircase design has a perfect blend of rustic and refined. The railing has double-end posts and flat bar railings.

Illustration of fabricated hollow form Metal stair stringer
Fabricated hollow form stair stringer
Hollow form floating stair stringer with flat bar railing and white oak treads and handrail in rustic setting.
Hollow Form mono stringer stair

12) Saw Tooth Double Stringer Stair

A saw tooth steel plate double stringer stair with open risers adds a striking modern touch to this unique home. The cable railing system is the Ithaca Style that is fascia mounted to the stairs stringers.

Illustration of a double metal stair stringer in the saw tooth style.
Saw tooth double stringer
Saw tooth netal stair stringer with wood treads.
Double stringer saw tooth stair

13) Stair Treads Slice into Rectangular Mono Stringer

Create the illusion where the wooden stair treads appear to seamlessly slice through the stair’s steel mono stringer. To accomplish this stair style the steel stringer is notched to accommodate the wood tread. The result is a simple modern appearance.

Rendering of stair stringer and tread showing how to create the stringer so the tread appears to slice through it
Mono stringer with treads slicing into steel stringer
Finished stair with steel stringer and wood treads that appear to slice through the stringer
Wood treads slice into steel stringer

Stair Stringer Construction Tips

Stair Stringer

When constructing a stair stringer it is key to understand your local building code requirements for stairs before starting your project. For residential stairs, we follow the National (IRC) Code. Many municipalities adopt this code but some allow variations that might either tighten or loosen the requirements. The next step in the construction of a stair is to take an accurate measurement of the floor-to-floor dimensions, and then divide this by an even number for the tread positions not to exceed 7-3/4 in (IRC code) tread rise (vertical back part of a step) with a minimum of 10 in tread run (horizontal part of a step).

The ideal stair is considered to have a 7-in rise and 11-in run. You want to dimension as close to these numbers as your space will allow. Keep in mind that the riser opening can not exceed 4 inches. Your tread rise minus the 4″ gap will determine the thickness of the tread that will be required. If a thinner tread is desired, a bent angle near the front edge of the tread may be required to ensure the maximum 4″ gap is maintained.

Illustration showing how to measure floor to floor dimensions for Stair Stringers
Floor-to-floor measuring for stair stringers
Tread rise and run description
Rise and Run Spacing Requirements

Base and Top Plate Options

The top mounting plate of the stringer and hardware can be designed to be exposed or concealed. Leaving the plates and bolts exposed has a rustic industrial appeal and has a little more installation flexibility (and less cost) to install than the concealed approach. Concealing the plates results in a clean, minimal appearance, however, it takes a little more planning and finesse to hide the plate and hardware.

Similarly, the bottom mounting plate can be exposed or recessed into the floor. This will require blocking underneath the floor to provide a structure for mounting the base plate to.

Illustration of stair stringer mounting plate with exposed plate and hardware
Exposed Mounting Plate
Stair stringer with concealed or exposed hardware
Concealed Mounting Plate

Railing Type and Mounting

The type of railing and how it will attach to the stair treads must be designed into the overall stair stringer system. Some considerations are whether the railing posts are designed to be surface mounted, fascia mounted or attached to the stringer under the treads.

Also, the type of railing system chosen may have different structural and attachment requirements. For example, stairs with cable railings must be designed to handle the lateral loads imposed by the cable tension. A metal bar railing or glass railing can actually add structural rigidity to the stair system.

The type of tread material also must be considered. Wood treads, glass treads, and stone treads all impart very different design requirements to the underlying stringer.

The good news is that we work all this out for you during our design process.

Posts are under-mounted to the stringer
Posts are fascia mounted to stringers
Posts are surface mounted on treads

If you found this helpful you may also like the following:

Illustration of bifurcated stair
Types of Stairs
zig zag stair with wood treads and cable railings
6 Types of Stair Treads
wood tread with spindle railing and metal single stringer
How to Choose Wood for stair treads

At Keuka Studios, we custom fabricate residential and commercial stairs and railings to fit your style, space, and requirements. To learn more about how each cable railing project moves from vision to reality. Take a look at our custom railing design process. We take pride in building craftsman-quality residential and commercial-grade stairs and railings for interior and exterior applications. Contact us to get started on your project.

Share and Enjoy !