Technical guide
The essentials for choosing and specifying a sandwich panel.
Which core to choose
| Core | Conductivity λ (W/mK) | Fire | Weight | Best for |
|---|---|---|---|---|
| PUR (polyurethane) | 0.021–0.024 | Good (C-s3,d0 to B-s2,d0) | Light | Roofs and façades in hot climates; best price/insulation ratio |
| PIR (polyisocyanurate) | 0.021–0.023 | Better (B-s2,d0 / B-s1,d0) | Light | Buildings with stricter fire requirements, cold rooms |
| Mineral wool | 0.038–0.042 | Non-combustible (A2) | Heavy | Fire compartments, high acoustic absorption |
Typical industry values as a guide; always confirm against the product datasheet.
Which thickness to use
Roofs in hot climates. The most common choice, in stock.
More comfort and less air-conditioning; longer spans.
Chilled storage (0 to 5 °C), high-performance façades.
Freezing (−18 °C), low-temperature rooms.
How a roof is installed
- 1
Structure
Purlins roughly every 1.50 m, levelled. Double purlin at end-laps.
- 2
Fixing
Panels side by side with self-drilling screws and washers; sealant at laps.
- 3
Trims
Ridge, front, side flashings and gutter made to measure to prevent leaks.
A crew installs 100–150 m² a day: 600 m² is done in under a week.