Floating Staircase with Frameless Glass Railing
Austin, Texas, USA — Private 4-bedroom residential villa, 2-storey, contemporary design
The homeowners wanted the staircase to be the living room's visual anchor — not an afterthought at the back of the hall. A single powder-coated steel mono-stringer anchored into the poured concrete slab carries 14 American white oak treads, each cantilevered 900 mm with zero visible support hardware. At the treads' open edge, 12 mm ultra-clear low-iron glass panels create an unbroken transparent barrier that preserves the hillside view beyond.
Project value: USD 24,000 – 28,000
The Challenge
The concrete slab-to-slab height of 3,280 mm was non-standard, requiring a custom stringer with 13 tread positions (rather than the standard 12 or 14). The open-plan living room below meant that the stringer had to be fully concealed within the wall cavity — the stringer had to be installed first (before drywalling), then the architect had to drywall around it. This created a tight coordination sequence between our structural drawing delivery and the builder's framing schedule. Additionally, Austin is in a mild seismic zone (Seismic Design Category B), requiring the anchor bolt design to include both horizontal and vertical load components.
Our Solution
We produced a custom stringer of 200×100×8 RHS mild steel with 13 tread bracket positions at 252 mm vertical centres, hot-dip galvanized internally before powder coating externally. The anchor plate was designed with 4 × M20 Hilti HIT-RE 500 V4 chemical anchors into the slab (pull-out tested to 45 kN each). A timed drawing sequence was provided: structural drawing for building permit (week 1), anchor bolt layout drawing for concrete phase (week 3), finish drawing for drywalling coordination (week 6). Oak treads were supplied pre-drilled to mate with stringer bracket holes — no on-site drilling of timber required. Glass panels were shipped in a second consignment after on-site post positions were confirmed, cut precisely to the as-installed post spacing.
The Result
The staircase was installed in 3 days by the builder's joinery team (no specialist stair contractor required). Building control inspection passed first time. The homeowners described the result as "the first thing every guest notices." The architect specified the same stringer-and-glass system for two subsequent projects.
Technical Deliverables
- Stringer — Custom 200×100×8 RHS, 13 tread positions, galv + black powder coat RAL 9005
- Treads — American white oak, 40 mm thick, 1,100×280 mm, pre-oiled (Rubio Monocoat Pure)
- Glass — 12 mm Pilkington Optiwhite low-iron toughened, 1,048×900 mm panels (custom cut)
- Posts — SUS 316 brushed spigot posts × 5, floor-fix, with EPDM rubber isolators
- Handrail — SUS 316 brushed round handrail 50 mm Ø, wall-mount end brackets both ends
- Structural — IBC 2021 calcs, PE-stamped (TX license), 200 lbf guardrail load verified
- Packaging — Stringer in timber-slatted crate; treads in individual foam wraps; glass in A-frame wooden crate
- Logistics — Changzhou → Houston (LCL consolidation), 5-week transit, door-to-door
"The drawing package was so complete that our building inspector signed off without a single query. The stringer arrived exactly as spec'd — we had it plumbed and anchored in a morning."
Project Scope
- ▸One flight floating straight staircase (mono-stringer, black powder coat)
- ▸American white oak solid timber treads × 14 steps
- ▸Frameless glass balustrade, 12 mm toughened low-iron ultra-clear glass
- ▸Stainless steel 316 spigot post system
- ▸Round stainless 316 brushed handrail, 50 mm Ø
- ▸IBC structural calculations and PE-stamped drawings