One of the most common applications for bespoke glass is on staircases, but it is also one of the areas where getting the specification wrong can have serious consequences. Whether you’re replacing old wooden spindles or installing a completely frameless system, the glass must be safe, compliant, and fit for purpose.
The Difference Between Infill Panels and Structural Glass
The specification is largely the same for side panels, full-height under-stair infills, or landing panels — what matters most is whether there is a handrail taking the load.
When 8 mm or 10 mm Toughened Glass Is Usually Fine (Infill Panels)
If the glass is installed in base rails or between newel posts with clamps and there is a timber or steel handrail above it, then 8 mm or 10 mm toughened glass is normally sufficient. In this case the glass acts only as an infill panel, not the primary structural barrier.
When You Must Use Toughened Laminated Glass
If the glass is side-fixed (bolted) to the stringer with no handrail, the glass itself becomes the barrier. In these frameless systems, toughened laminated glass (typically 13.5 mm or 17.5 mm) is usually required.
Getting this wrong can create a serious fall hazard. If the glass breaks, there is no longer a barrier. Even if less severe, the installation may fail building control inspection.
Note: Stair treads or walk-on glass require a completely different specification — nearly always a triple toughened laminate such as 33.04 mm.
Minimum Height Requirements
- Domestic stairs and landings (inside homes): Minimum 900 mm high
- Balconies, roof terraces, and external platforms: Minimum 1100 mm high
- Commercial or public buildings: Usually 1100 mm (always confirm with specific design criteria)
These measurements are taken from the finished floor level to the top of the handrail or guard.
Load-Bearing and Strength Standards
All balustrades must comply with BS 6180:2011 – Barriers in and about buildings. They need to withstand both static loads (people leaning) and dynamic impact forces.
- Domestic installations: minimum 0.36 kN/m
- Public / high-traffic areas: up to 3.0 kN/m depending on expected crowd loading
Gaps and Openings (Approved Document K)
No opening in the balustrade should allow a 100 mm sphere to pass through (roughly the size of a small child’s head). This applies to both vertical and horizontal designs and is a very common point of failure during building control inspections.