Polycarbonate Thermal Expansion: Gap Calculator & Fixing
Thermal expansion calculator (0.065 mm/m/C) and fixing design rules for polycarbonate panels. Expansion gap quick reference table.
Polycarbonate expands and contracts as temperature changes. Use this worksheet to estimate movement before sizing fixing holes and edge clearance. The result is a procurement and detailing input, not structural approval.
Thermal expansion formula
Movement (mm) = panel length (mm) × coefficient of linear thermal expansion (/°C) × temperature change (°C).
For a preliminary estimate, polycarbonate is commonly calculated near 0.065–0.070 mm/m/°C. Confirm the coefficient on the exact resin or sheet data sheet before issuing drawings.
Worked example
For a 3,000 mm panel, a 50°C design temperature range and a preliminary coefficient of 0.067 mm/m/°C: 3 m × 50°C × 0.067 = 10.05 mm total movement. The detail must distribute that movement between supported edges according to the glazing system.
Inputs to send with an RFQ
- Panel length and width
- Lowest and highest sheet temperature, not only ambient temperature
- Solid, multiwall or profiled sheet
- Framing material and fixing method
- Required wind, snow and service loads
Do not clamp the sheet rigidly or use this estimate as a substitute for system-supplier installation instructions. Hole allowance, washer size, edge engagement and support spacing must work together.
Request a project-specific recommendation
Send the sheet type, dimensions, quantity, application and required performance. Plastura will review the inputs needed for a comparable quotation.