An acrylic stair balustrade is a measurement job before it is a material job. A flight of stairs is a series of steps with a constant pitch, and every panel between the stringer and the handrail has a different vertical dimension because of where it lands.
A fit-out contractor in Manchester fitted 14 panels to a retail stair. Twelve were fine; two at the top landing had 18 mm gaps under the handrail, because the landing panel sits on a horizontal run and the raked panels do not.
Acrylic stair balustrade panels: sizes and templates
- Infill panel: 10 mm clear cast, posts at 900 mm centres
- Long span without a post: 12 mm, or add an intermediate post
- Raked edge: cut per panel from a site template
- Handrail height: 900 mm residential, 1100 mm commercial in most codes
The template is the part people skip. Cardboard or plywood templated against the actual stringer and the actual tread nosings, panel by panel, gives an edge that follows the pitch. A single raked cut repeated across a flight will be wrong at both ends.
Fixing the panel without cracking it
A balustrade panel is held at the bottom and touched at the top, which means the bottom fixing takes all the load. A slotted base plate with a 2 mm clearance hole and a rubber gasket lets the panel move; a bolt tightened into a drilled hole in 10 mm acrylic cracks within a season.
The handrail carries the lateral load, not the panel. Where the design has no handrail, the panel becomes the guard and the thickness, the span and the code requirement all change. That is a design conversation, not a panel order.
Clarity is a safety feature as well as an aesthetic one: a clear balustrade shows the tread edges, which matters on a stair with a change of level at the bottom. Frosted panels look softer but hide the nosings at a glance.
Where the stair also has a glass or acrylic guard at the landing, the details overlap with polycarbonate balustrade panels, which covers the impact-rated alternative, and with acrylic cut to size for the template-based ordering process.
Send your stair drawing, pitch and code requirement to oversales@rpplexiglass.com for a balustrade panel quote.
Frequently Asked Questions
What thickness acrylic for a stair balustrade?
10 mm for infill panels between posts at 900 mm spacing, 12 mm where panels span without a post or where the code treats the panel as a guard. Thickness is set by the span, not by the stair height.
Can acrylic panels be fitted to a raked stringer?
Yes, but each panel needs its own template. Cutting a raked edge to a single angle across a flight leaves gaps at the top step. Measure every panel on site after the treads are laid.
Is acrylic allowed as a balustrade infill?
It depends on the code and the occupancy. Acrylic is not a rated barrier and some jurisdictions require laminated glass or a tested system. Confirm the local requirement before ordering panels.