Polycarbonate stadium glazing is a wind-load calculation that happens to look like architecture. A stadium operator in the Gulf replaced nine cracked polycarbonate panels in one season, each time with a crane and a night shift. The panels were not defective. The fixing detail clamped the sheet rigidly at both ends of a 3 m span, and the daily thermal cycle did the rest.
Polycarbonate stadium glazing thickness by span
Stadium glazing sees wind suction as the dominant case: a large roof or facade panel acts as a sail, and local pressure coefficients near corners and edges can be two to three times the average.
For a 3 m span, design practice lands at 15 to 20 mm solid polycarbonate or a laminated build with comparable stiffness. A 10 mm panel on the same span deflects visibly under gust and works the gasket loose within a season.
Deflection limits usually govern before stress limits do. A 3 m panel limited to span over 60 is a stiffer requirement than the same panel limited to yield.
Fixing patterns that survive thermal cycling
Polycarbonate expands about 0.05 mm per metre per degree Celsius. On a 3 m panel with a 40 degree daily swing, that is 6 mm of movement per panel. A fixing pattern that prevents that movement converts it into stress at the hole.
- Fix one edge rigidly, allow the opposite edge to slide
- Oversize holes by 2 to 3 mm in the sliding direction
- Use isolating washers with a sealing bead, not direct metal contact
- Keep fixings at least 30 mm from the panel edge
- Never place a fixing at a re-entrant corner
The last two are the ones that appear in failure reports. A fixing close to an edge, or at a corner, starts the crack that ends the panel.
Edge distance and the crack that follows
Stress concentrates at holes. Thirty millimetres from a 3 m panel edge is a workable minimum; forty is better, and the cost difference is one row of framing.
Where a panel must be fixed near a corner for structural reasons, an oversized washer spreads the load and a drilled relief hole stops a crack from propagating.
Replacement access, decided at design
Stadium panels eventually need replacing, whether from impact, vandalism or a failed seal. A removable bead system, with the panel small enough to lift from inside the bowl, turns a crane job into a two-person task.
Panels above 2.5 square metres rarely meet that test. Splitting a large opening into two panels with a mullion is often the cheaper lifetime decision, even though it looks less pure on the drawing.
Maintenance and the appearance budget
Polycarbonate with a UV coextrusion holds clarity for eight to ten years outdoors, and structural integrity for much longer. Cleaning twice a year with a neutral detergent and a soft brush is the whole regime; abrasive pads and alkaline cleaners shorten the life of both faces.
Where the panel is also a barrier, as on concourse edges, the polycarbonate balustrade guide covers the additional load cases. For enclosures and shelters at the same site, the bus shelter note deals with the smaller spans.
Ask for the fixing pattern and the replacement method in the same document as the panel schedule. They belong together, and separating them is how the crane bill appears.
Send spans, wind loading and access constraints to oversales@rpplexiglass.com for a panel schedule and fixing proposal.
Frequently Asked Questions
What thickness for stadium glazing on a 3 m span?
Typically 15 to 20 mm solid polycarbonate, or a laminated build. The governing case is usually wind suction on the outer panel, not the crowd load.
Why does stadium polycarbonate crack at fixings?
Rigid clamping with a mismatch between the panel and the steel frame expansion. Oversize holes, isolating washers and a defined movement direction prevent it.
Can panels be replaced without scaffolding?
Yes, if the design uses a removable bead system and the panel is small enough to be lifted from inside. That decision is made at design, not at maintenance.