Polycarbonate U-Value Guide: Insulation Performance of PC Sheets (W/m²K, 2026)
4 mm twin-wall polycarbonate has a U-value of about 3.3 W/m²K; 10 mm twin-wall drops to 2.5 W/m²K; 16 mm triple-wall reaches 1.8 W/m²K; 25 mm 5-wall achieves 1.2 W/m²K.
Short answer: a polycarbonate U-value is valid only for a named sheet structure, thickness, orientation and test method. Solid sheet and multiwall sheet cannot share one generic value. Use supplier test data for the exact product before energy-code or condensation calculations.
What determines polycarbonate U-value?
- Structure: solid, twin-wall, triple-wall and multiwall geometries transfer heat differently.
- Thickness and air chambers: additional chambers usually improve insulation, but the result is product-specific.
- Installation: framing, edge closures, fasteners and air leakage affect the assembled system.
- Test basis: compare values reported to the same standard and conditions; do not mix centre-of-sheet and whole-assembly values.
Specification workflow
- Define the required whole-assembly thermal target.
- Select the sheet family and minimum light-transmission requirement.
- Request the exact product data sheet and test report.
- Let the project engineer account for framing, joints, interior conditions and condensation risk.
Plastura can match a quotation to sheet structure, thickness, colour and project conditions. Final code compliance and system-level thermal calculations remain the designer’s responsibility.
Typical U-value by sheet structure
| Structure | Thickness | U-value (W/m²K) |
|---|---|---|
| Twin-wall | 4 mm | ~3.3 |
| Twin-wall | 10 mm | ~2.5 |
| Triple-wall | 16 mm | ~1.8 |
| 5-wall multiwall | 25 mm | ~1.2 |
Values are centre-of-sheet figures for standard clear structures; request the product datasheet for tested numbers for your exact specification.
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.