Sandwich Panels or Rock Wool: Choosing Wall Cladding Right

PU insulates best, rock wool resists fire, glass wool saves money — match the panel to the building.

Envelope panels are 10–15% of a plant's cost but drive most of the day-to-day experience. The logic for three mainstream options:

PUR/PIR sandwich: lowest thermal conductivity (~0.022 W/m·K), first choice for insulation; 50–100mm for cold rooms and climate-controlled shops; PIR outperforms PUR in fire class.

Rock wool sandwich: non-combustible Class A — mandatory at fire walls and compartment lines; insulation below PU, so thickness grows about 30% for the same R-value, and it's heavier.

Glass wool + steel sheets: lowest cost, fine for ordinary warehouses; in humid buildings add a vapor barrier or the wool saturates and fails.

Bottom line: climate control — PU; fire separation — rock wool; standard warehouse — glass wool. Mixing (PU roof, rock-wool gables) is common on high-spec projects.