Mono Stringer Stairs
What Is a Mono Stringer Stair
Single Steel Beam and Treads
Local Fabrication
Every stringer welded, ground, and finished in our Kent shop
Excellent Reputation
Consistently top-rated by homeowners, builders & designers
Professional Showroom
Stop by to see samples in person, compare finishes, hardware and details, feel the materials, and confidently choose what fits your space.
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Floating Stairs Types
Mono Stringer vs Double Stringer vs Cantilever
Treads are supported by one central steel stringer.
- Clean and modern profile
- Open feel with less steel
- Strong support for daily use
Best for modern spaces.
Treads are supported by two steel stringers.
- Very strong support system
- Great for wider stair runs
- Stable feel underfoot daily
Best for high-traffic spaces.
Treads are anchored into a structural wall support.
- True floating stair effect
- Minimal visible structure
- Most open appearance
Best for minimalist spaces.
Why Choose a Mono Stringer Stair
Four Reasons Mono Stringer Stairs Work So Well
Minimal Visual Footprint
Open Sight Lines
Engineered Strength
Material Flexibility
Application Areas
Mono Stringer Stairs Application
Mono stringer floating stairs read beautifully in open-plan homes, lofts, and modern new builds. We have installed them in homes across Seattle, Bellevue, Mercer Island, Kirkland, and the rest of the greater Puget Sound. In Seattle specifically, they tend to land in Fremont, Ballard, South Lake Union, Eastlake, Wallingford, and Capitol Hill, where modern new construction and post-WWII remodels both reward an open stair.
A mono stringer also performs well in second-story additions and basement conversions, where every square foot matters and a traditional boxed staircase would eat up the room. Because the stair sits on a single beam rather than two outside stringers, it can be tucked closer to walls and corners, giving you back floor area that a closed stair would have consumed.
Quick Estimate
Stairs & Railings
Pair Mono Stringer Stairs with Railings
by Custom Railings WA
A mono stringer stair looks best when the railing matches the open feel of the structure. Our sister company, Custom Railings WA, fabricates the railings for every staircase we build, so the stair design and the railing design come out of the same conversation. The most popular pairings are frameless glass for a fully open look, cable infill between thin steel posts for a modern industrial style, and slim metal pickets for a more traditional aesthetic.
Areas Served
We Serve Cities Across the Puget Sound Region & Beyond
We design and install mono stringer floating staircases throughout the Pacific Northwest.
FAQ
Mono Stringer Stairs: Common Questions
What is a mono stringer staircase?
A mono stringer staircase is a floating-stair design where every tread is supported by a single steel beam running down the center, with the treads cantilevered out on either side of that beam. The result is a clean, modern stair that looks like the treads are floating, with only one piece of visible structure connecting them.
How much do mono stringer stairs cost?
Most custom mono stringer stairs we build in Seattle start at around $14,000 and run up to $30,000 or more, depending on run length, tread material, steel finish, and railing system. A standard straight-run with oak treads and a powder-coated steel beam sits at the lower end. Wider runs, premium hardwoods like walnut, and integrated LED lighting push the price up.
Are mono stringer stairs safe?
Yes, when properly engineered and installed. The central steel beam is engineered to carry the live load of every tread, and tread-to-beam connections are designed for decades of daily use without movement or wear.
What tread materials work with mono stringer stairs?
Solid hardwood is the most common choice: red oak, white oak, walnut options in stain or natural finishes. Steel treads, concrete-topped treads, and mixed-material options are also available for commercial or industrial-look projects. If you have a species or finish in mind that is not on the standard list, bring it to the consultation. We source a lot of custom material.