Last updated: May 20, 2026
Quick Answer
A PU sandwich panel thickness chart maps polyurethane core depths — typically ranging from 30 mm to 200 mm — to specific applications such as cold storage, warehouses, clean rooms, and agricultural buildings. Thicker panels deliver lower U-values (better thermal resistance), while thinner panels suit interior partitions and mild-climate walls. Choosing the wrong thickness is one of the most common and costly mistakes in insulated panel construction.
Key Takeaways
- Standard PU sandwich panel thicknesses run from 30 mm (interior partitions) to 200 mm (deep-freeze cold rooms), with 50 mm, 75 mm, 100 mm, and 150 mm being the most widely used sizes.
- Cold storage applications almost always require 100 mm to 200 mm PU panels depending on target temperature — thinner panels lead to energy loss and condensation problems.
- PU foam has one of the highest thermal resistance values among common insulation core materials, with a thermal conductivity (λ) of approximately 0.022–0.025 W/m·K (industry-standard range; verify with your supplier's test certificate).
- Fire rating changes with thickness: thinner panels (under 50 mm) generally achieve lower fire classifications; panels above 100 mm with fire-retardant additives can reach Class B or better under EN 13501-1.
- Humidity resistance is strong but not absolute — PU panels perform well in high-humidity environments when joints are properly sealed and facing materials are corrosion-rated.
- Cost increases roughly linearly with thickness, though 100 mm panels often represent the best value per unit of thermal performance for most commercial applications.
- Mistakes to avoid: under-specifying thickness for cold rooms, ignoring local climate data, and selecting panels based on price alone without checking U-value certification.
- Industries that rely on PU panels include food processing, pharmaceuticals, cold chain logistics, poultry farming, and cleanroom construction.
What Is a PU Sandwich Panel and How Thick Can They Get?
A PU (polyurethane) sandwich panel is a three-layer building component: two rigid metal facings (usually pre-painted steel or aluminum) bonded to a rigid polyurethane foam core. The foam core is injected and cured under pressure, creating a monolithic, high-density insulation layer that also provides structural rigidity.
Thickness range: PU sandwich panels are manufactured from as thin as 30 mm up to 250 mm, though the practical commercial range is 50 mm to 200 mm. Custom thicknesses beyond 200 mm are available from specialist manufacturers but carry longer lead times and higher costs.
| Core Thickness | Typical U-Value (W/m²K)* | Primary Use Case |
|---|---|---|
| 30–40 mm | 0.55–0.65 | Interior partitions, mild-climate walls |
| 50 mm | 0.40–0.45 | Office dividers, light industrial walls |
| 75 mm | 0.28–0.32 | Warehouse walls, general industrial |
| 100 mm | 0.20–0.23 | Cold rooms (+2°C to +10°C), roofs |
| 150 mm | 0.14–0.16 | Blast freezers, deep-freeze rooms |
| 200 mm | 0.10–0.12 | Ultra-low temperature storage (−25°C and below) |
U-values are indicative estimates based on a λ of ~0.023 W/m·K for standard PU foam. Always request certified test data from your supplier.
For a broader look at how thickness decisions apply to roofing specifically, see this guide to sandwich panel roof thickness.
Standard Thickness Ranges for Different Construction Applications
Different building types demand different insulation performance. The PU sandwich panel thickness chart below covers the most common applications:
Walls:
- Interior office partitions: 30–50 mm
- General industrial walls: 50–75 mm
- Warehouse exterior walls: 75–100 mm
- Cleanroom walls: 50–100 mm (depends on ISO class)
- Cold room walls (+2°C to +10°C): 100–120 mm
- Freezer room walls (−18°C to −25°C): 150–200 mm
Roofs:
- Standard industrial roof: 75–100 mm
- Cold storage roof: 150–200 mm (roofs lose more heat than walls — always go thicker)
Floors (where PU panels are used):
- Light-duty cold room floors: 100–150 mm
- Heavy-duty freezer floors: 150–200 mm
Decision rule: If you're unsure between two thicknesses, go with the thicker option for any refrigerated application. The energy savings over 5–10 years almost always outweigh the upfront cost difference.
For a full breakdown of how to match thickness to your specific project, the sandwich panel thickness selection guide covers climate zones, load requirements, and compliance factors in detail.
How Do Polyurethane Sandwich Panels Compare to Other Insulation Materials?
PU panels outperform EPS (expanded polystyrene) and mineral wool on thermal resistance per millimeter. This means a 100 mm PU panel achieves roughly the same insulation as a 140–160 mm EPS panel — a significant space and weight saving.
Core material comparison:
| Core Material | Thermal Conductivity (λ) | Fire Performance | Moisture Resistance | Relative Cost |
|---|---|---|---|---|
| Polyurethane (PU) | ~0.022–0.025 W/m·K | Moderate (additive-dependent) | Good | Medium–High |
| EPS (polystyrene) | ~0.035–0.040 W/m·K | Lower (melts/burns) | Moderate | Low–Medium |
| Mineral wool / Rockwool | ~0.033–0.040 W/m·K | Excellent (non-combustible) | Moderate | Medium |
| PIR (polyisocyanurate) | ~0.020–0.023 W/m·K | Better than PU | Good | High |
Choose PU if: thermal efficiency per millimeter is the priority, space is limited, or the application involves refrigeration.
Choose Rockwool if: fire safety is the overriding concern (e.g., high-occupancy buildings). See the rockwool vs. fire safety comparison for more detail.
Choose EPS if: budget is tight and thermal performance requirements are modest.
For a direct side-by-side breakdown, the EPS vs PU sandwich panel guide is worth reviewing before finalizing your specification.
Are PU Sandwich Panels Good for Cold Storage Buildings?
Yes — PU sandwich panels are the industry standard for cold storage construction. Their low thermal conductivity minimizes heat ingress, which directly reduces refrigeration energy costs and maintains stable internal temperatures.
Recommended thicknesses for cold storage:
- Chill rooms (+2°C to +10°C): 100 mm walls, 120–150 mm roof
- Medium-freeze rooms (−5°C to −18°C): 150 mm walls and roof
- Deep-freeze rooms (−20°C to −30°C): 200 mm walls and roof
The roof always needs to be at least one thickness grade above the walls because heat rises and solar gain adds load. For a complete walkthrough of cold room panel selection and installation, see the PU sandwich panel cold room guide.
Common mistake: specifying 100 mm panels for a −20°C freezer to save money. The compressor runs harder, energy bills rise, and the payback period for the cheaper panels is negative within 18–24 months in most climates.
Recommended Panel Thickness for Agricultural Cold Storage and Poultry Farms
Agricultural cold storage — including produce chillers, meat storage, and poultry farm temperature control — follows the same core logic as commercial cold rooms but with added considerations for humidity, cleaning cycles, and biological contamination.
Agricultural cold storage thickness recommendations:
- Produce chill storage (+2°C to +8°C): 100–120 mm
- Meat/fish cold room (−2°C to +4°C): 120–150 mm
- Poultry farm climate control (18°C to 24°C internal): 50–75 mm walls, 100 mm roof
For poultry applications specifically, panels must also resist ammonia vapors and frequent washdowns. Stainless steel or food-grade coated facings are recommended alongside appropriate core thickness. The poultry farm sandwich panel guide covers facing material selection alongside thickness decisions.
What Thickness Do I Need for Warehouse Wall Insulation?
For standard warehouse walls in a tropical or subtropical climate (such as Bangladesh or Southeast Asia), 75 mm to 100 mm PU panels are the practical recommendation. In temperate climates with mild winters, 50–75 mm may suffice for non-refrigerated storage.
Factors that push you toward thicker panels:
- High ambient temperature differential (outside vs. inside exceeds 15°C)
- Air-conditioned warehouse (100 mm minimum)
- Pharmaceutical or food-grade storage (100 mm+)
- Long panel spans without intermediate supports (thicker panels have higher bending stiffness)
Factors that allow thinner panels:
- Non-climate-controlled storage
- Interior partitions only
- Short panel spans with frequent structural supports
For warehouse-specific guidance, the sandwich panel warehouse guide for Bangladesh includes local climate data and practical sizing examples.
Fire Rating Differences Between Thin and Thick PU Sandwich Panels
Thicker PU panels do not automatically achieve better fire ratings — fire performance depends primarily on the foam formulation (fire-retardant additives) and the facing material, not just thickness. However, thickness does affect how long a panel assembly resists fire spread in practice.
Key points:
- Standard PU foam is combustible. Fire-retardant (FR) grade PU foam significantly reduces flame spread and smoke development.
- Under EN 13501-1, FR-grade PU panels typically achieve Class B or C, while standard PU panels may only reach Class D or E.
- Panels above 100 mm with FR foam and steel facings can achieve EI 30 or EI 60 fire resistance (30 or 60 minutes integrity/insulation) in tested assemblies.
- For buildings with strict fire codes — hospitals, cleanrooms, food processing plants — always specify FR-grade panels and request third-party fire test certificates.
For fire-rated panel options and compliance requirements, see the fire rated sandwich panel guide.
Can PU Sandwich Panels Work in High-Humidity Environments?
PU sandwich panels perform well in high-humidity environments when correctly specified and installed. The closed-cell structure of PU foam resists moisture absorption far better than open-cell alternatives like mineral wool. However, the facing material and joint sealing are the critical variables.
For high-humidity applications (food processing, washdown areas, tropical climates):
- Use galvanized steel or stainless steel facings with appropriate coating ratings
- Seal all panel joints with approved polyurethane sealant
- Install vapor barriers on the warm side in cold storage applications
- Avoid exposed cut edges — factory-finished tongue-and-groove joints are preferred
Edge case: In coastal or marine environments, standard galvanized facings may corrode within 5–7 years. Specify aluminum facings or high-durability PVDF coatings for these locations.
How Temperature Affects PU Sandwich Panel Performance
PU foam's thermal conductivity increases slightly at very low temperatures and can degrade at sustained high temperatures (above 80°C–100°C). For standard construction applications (−30°C to +60°C ambient), PU panels perform within their rated specifications without significant degradation.
Practical implications:
- In deep-freeze applications below −30°C, verify that the panel's foam density and facing adhesion are rated for that range — not all panels are.
- In industrial settings with process heat (kilns, ovens, high-heat manufacturing), PU panels are not appropriate. Mineral wool panels are the correct choice above 80°C sustained exposure.
- Thermal cycling (repeated freeze-thaw) can stress panel joints over time. Proper installation with flexible sealants mitigates this.
Average Cost of PU Sandwich Panels Per Square Meter
PU sandwich panel pricing varies by thickness, facing specification, order volume, and supplier location. The following are indicative price ranges for the Bangladesh market as of 2026 (estimates based on market-standard pricing; confirm with suppliers for current quotes):
| Thickness | Estimated Price Range (BDT/m²) |
|---|---|
| 50 mm | 900–1,200 |
| 75 mm | 1,100–1,500 |
| 100 mm | 1,350–1,800 |
| 150 mm | 1,800–2,400 |
| 200 mm | 2,300–3,000 |
These are estimates only. Actual prices depend on steel gauge, coating type, order quantity, and current raw material costs. Always request a formal quotation.
For current market pricing with installation costs included, the sandwich panel price per square meter guide provides detailed breakdowns.
Mistakes to Avoid When Selecting Sandwich Panel Thickness
Getting the PU sandwich panel thickness chart right matters — but these are the errors that most commonly lead to project failures:
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Under-specifying for cold rooms. The most expensive mistake. A 75 mm panel in a −18°C freezer will cost significantly more in energy over its lifetime than the savings made upfront.
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Ignoring roof vs. wall differences. Roofs need thicker panels than walls in nearly every application. Many buyers spec the same thickness for both.
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Not accounting for local climate. A 50 mm wall panel that works in a temperate European climate may be wholly inadequate in a 38°C tropical environment.
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Choosing thickness without checking U-value certification. Two panels of the same nominal thickness can have different foam densities and very different actual U-values. Always ask for the certified test report.
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Overlooking joint design. Even a correctly specified panel will underperform if joints are poorly sealed. Thermal bridging at joints can account for 15–25% of total heat loss in a cold room (estimate based on standard thermal bridge calculations; verify with your engineer).
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Assuming thicker always means better fire performance. Fire rating is about foam grade and facing type, not thickness alone.
For a structured decision process, the complete guide to choosing sandwich panel thickness walks through each variable step by step.
Which Industries Typically Use PU Sandwich Panels?
PU sandwich panels are used across any industry where thermal control, hygiene, or rapid construction is a priority.
Primary industries:
- Cold chain logistics: warehouses, distribution centers, blast freezers
- Food and beverage processing: production halls, cleanrooms, packaging areas
- Pharmaceuticals: temperature-controlled storage, GMP cleanrooms
- Poultry and livestock farming: climate-controlled housing
- Healthcare: hospital operating theaters, sterile rooms
- Industrial manufacturing: factories requiring climate control or acoustic separation
For cleanroom-specific applications — including ISO class requirements — the cleanroom sandwich panel guide provides ISO-class-by-class thickness recommendations.
Common Installation Problems with PU Sandwich Panels
Even correctly specified panels can fail if installation is poor. The most frequent problems:
- Thermal bridging at fixings: Metal fasteners conduct heat through the panel. Use thermal break washers and follow manufacturer fixing patterns.
- Improper joint sealing: Gaps at panel joints allow moisture ingress and heat transfer. Use the correct sealant type and apply it continuously.
- Incorrect panel orientation: Some panels are directional (tongue-and-groove profiles must align). Installing upside-down or reversed traps water in joints.
- Cutting without sealing edges: Cut edges expose the foam core to moisture. Always seal cut edges with compatible sealant or edge caps.
- Over-tightening fasteners: Compresses the panel facing and can crack the foam core near the fixing point.
FAQ
Q: What is the most common PU sandwich panel thickness for general industrial use?
A: 75 mm to 100 mm is the most common range for general industrial walls and roofs. It balances thermal performance, structural rigidity, and cost for most non-refrigerated applications.
Q: Can I use a 50 mm PU panel for a cold room?
A: Only for very mild chill rooms (+10°C to +15°C) in temperate climates. For anything below +10°C, 100 mm is the minimum recommended thickness. Using 50 mm in a standard cold room will result in high energy consumption and potential condensation on the panel surface.
Q: How do I read a PU sandwich panel thickness chart?
A: Match your target internal temperature (or climate control requirement) to the recommended core thickness, then check the corresponding U-value to confirm it meets your energy code or design specification. Always cross-reference with your structural engineer for span and load requirements.
Q: Does a thicker PU panel always have a better U-value?
A: Yes, for the same foam formulation — U-value decreases (improves) as thickness increases. But foam density and quality also affect U-value, so a high-density 100 mm panel may outperform a low-density 120 mm panel from a different supplier.
Q: What is the minimum thickness for a pharmaceutical cold room?
A: Pharmaceutical cold rooms storing products at +2°C to +8°C (standard refrigerated storage) typically require 100 mm walls and 120–150 mm roofs. GMP guidelines and local regulations may impose additional requirements.
Q: Are PU sandwich panels waterproof?
A: The steel facings are waterproof; the PU foam core is highly moisture-resistant due to its closed-cell structure. However, water can enter through unsealed joints or damaged facings. Proper installation and regular maintenance are essential.
Q: How long do PU sandwich panels last?
A: With correct installation and maintenance, PU sandwich panels have a service life of 20–30 years. The foam core does not degrade significantly over time under normal conditions, but facings can corrode if the coating is damaged.
Q: What thickness is used for hospital operating theaters?
A: Hospital OT rooms typically use 50–75 mm PU panels for walls and 75–100 mm for ceilings, combined with specific hygienic facing materials. The priority is surface hygiene and airtightness rather than deep thermal insulation.
Q: Is 200 mm the maximum available PU panel thickness?
A: 200 mm is the standard maximum for most manufacturers. Some suppliers offer 220–250 mm for specialized ultra-low-temperature applications, but these are custom orders with longer lead times.
Q: Do thicker panels cost significantly more to install?
A: Material cost increases roughly proportionally with thickness. Installation labor is similar across thicknesses for the same panel area. The main added cost for thicker panels is handling (they're heavier) and the need for heavier structural supports in some designs.
Conclusion
The PU sandwich panel thickness chart is not a one-size-fits-all reference — it's a decision tool that connects your thermal, structural, and regulatory requirements to a specific panel specification. The core principle is straightforward: match the target temperature differential and application type to the appropriate core thickness, then verify with certified U-value data from your supplier.
Actionable next steps:
- Define your temperature requirements — know the internal and external design temperatures for your project before looking at any thickness chart.
- Check local energy codes — many markets have minimum U-value requirements for commercial buildings and cold storage. Confirm compliance before specifying.
- Request certified test data — ask suppliers for third-party U-value and fire rating certificates, not just product datasheets.
- Don't spec roofs and walls identically — always add at least one thickness increment to roof panels versus walls.
- Get a formal quote at your specified thickness — use the price estimates in this guide for budgeting only; confirm current pricing with your supplier.
- Consult a structural engineer for spans exceeding 6 meters or loads beyond standard design tables.
For full details on the benefits of PU sandwich panels and how they compare across building types, that resource is a practical next read.
References
- EN 13501-1: Fire classification of construction products and building elements. European Committee for Standardization (CEN). (2018)
- ISO 6946: Building components and building elements — Thermal resistance and thermal transmittance. International Organization for Standardization. (2017)
- ASHRAE Handbook — Refrigeration. American Society of Heating, Refrigerating and Air-Conditioning Engineers. (2022)
- European Insulation Manufacturers Association (EURIMA). Thermal insulation product standards and performance data. (2021)