PU vs PIR vs EPS vs Rock Wool Sandwich Panels: Complete Comparison Guide
Jul 24, 2026
Sandwich panels are typically constructed by bonding two layers of facing material—such as color-coated galvanized steel sheets, aluminum sheets, or fiberglass cloth—with an insulating core. Depending on the core material, they are classified into PU, PIR, EPS, and rock wool sandwich panels.
A comparative analysis of these types follows.
Performance iIndex
PU Sandwich Panel
PIR Sandwich Panel
EPS sandwich panel
Rock wool Sandwich panel
Thermal Conductivity(W/(m・K))
0.022-0.028
0.018~0.023
0.038-0.042
0.040-0.048
Density(kg/m³)
36~45 kg/m³
40~50 kg/m³
10~18 kg/m³
90~150 kg/m³
Hygroscopicity
≤ 3%
≤ 2%
Low (closed-cell structure, water absorption rate ≤ 4%)
High (porous structure, water absorption rate can reach 5%-10%)
Fire Rating
B2
B1
B2
Non-flammable (Class A), does not release toxic gases at high temperatures
Sound insulation performance
Moderate
Moderate
Lower
High
Weather Resistance
Better (its UV resistance is superior to EPS, but still requires protection)
Better than PU
Poor (Subject to aging and deformation due to long-term exposure to ultraviolet rays)
Excellent (resistant to high and low temperatures, anti-aging, unaffected by ultraviolet rays)
Compressive / Flexural Strength
Higher (with good toughness and strong impact resistance)
Better than PU, more stable
Medium (Susceptible to Impact Damage)
High (strong in rigidity, but with high brittleness, prone to cracking)
Cost
Higher
Highest
Lowest
Moderate
Based on the comparative analysis of the four types of core-material sandwich panels across various aspects:
PIR sandwich panels offer the best thermal insulation and better fire resistance, delivering high overall cost-effectiveness, they are suitable for high- and low-temperature cold storage, blast-freezing facilities, cold-chain logistics warehouses, and EU-standard industrial plants.
PU sandwich panels rank second in thermal insulation performance and are suitable for standard constant-temperature facilities, steel structure enclosures, temporary structures, and roofing or wall panels.
EPS sandwich panels provide good thermal insulation at a low cost; being lightweight and easy to install, they are ideal for simple industrial buildings, temporary modular structures, construction site hoarding, and warehouses with lower specifications.
Rock wool sandwich panels, distinguished by their superior fire resistance, are suitable for large shopping malls, office buildings, high-rise structures, hazardous chemical warehouses, explosion-proof workshops, and projects requiring Class A fire safety ratings.