What is PUR sandwich panel?
Polyurethane (PUR) foam is made by reacting a polyol with an isocyanate in roughly equal proportion in the presence of a pentane blowing agent; injected between two steel skins on a continuous line it expands, bonds to both faces and cures within minutes into a closed-cell foam of about 40 kg/m³ with a thermal conductivity of 0.024–0.026 W/mK — second only to PIR among panel cores and far ahead of mineral wool and EPS. The result is the light, stiff, cheap composite that made the insulated metal panel possible: a 50 mm PUR roof panel weighs 10 kg/m², spans 3 m and gives U ≈ 0.45 W/m²K. Its limits are thermal and fire-related: PUR softens above about 100 °C and, once ignited, burns with more smoke than PIR — tested to EN 13501-1 it typically classes B-s2,d0 to B-s3,d0, which many European insurers and the codes for larger buildings no longer accept, and which is why PIR has replaced it in most of the EU. In the markets we serve — Iraq, the Gulf, Africa, Central Asia — PUR remains the standard for sheds, warehouses, camps, agricultural and prefab buildings where no fire class is written into the specification, at about 5 % below PIR and 25 % below rockwool. It performs identically to PIR in water resistance, dimensional stability (−30 to +90 °C) and durability. We produce PUR roof (5-rib) and wall (micro-rib, lined) panels in 40–120 mm, 1 000 mm cover, lengths to 14 m, with 0.40–0.50 mm PPGI skins; on request the same line runs PIR for the parts of a project that need the better fire class.
Grades, standards and tolerances
| Grade / standard | Yield (MPa) | Note |
|---|---|---|
| PUR core, 38–42 kg/m³, pentane-blown | λ 0.024–0.026 W/mK | B-s2,d0 / B-s3,d0 to EN 13501-1; EN 13165 |
| Compressive strength | ≥ 0.10 N/mm² | at 10 % deformation |
| Service temperature | −30 to +90 °C | |
| Water absorption | < 3 % vol. | closed cell |
| Skins DX51D + Z100–Z140 + PPGI | ≈ 140 | EN 10346 / EN 10169 |
Declared values per EN 14509 CE marking. For B-s1,d0 or insurer requirements specify PIR.
PUR panel thickness and U-value
| Thickness | U-value (W/m²K) | Weight (kg/m²) | Purlin / girt spacing (0.75 kN/m²) | Typical use |
|---|---|---|---|---|
| 40 mm | 0.56 | 9.8 | 2.8 m | sheds, camps, canopies |
| 50 mm | 0.46 | 10.2 | 3.3 m | warehouses, workshops |
| 60 mm | 0.38 | 10.6 | 3.7 m | light heating |
| 80 mm | 0.29 | 11.4 | 4.3 m | heated halls |
| 100 mm | 0.23 | 12.2 | 4.9 m | offices, chillers |
| 120 mm | 0.20 | 13.0 | 5.4 m | cold stores (PIR preferred) |
PUR runs about 10 % behind PIR in U-value at equal thickness; spans are the same.
When PUR is enough — and when to move to PIR or rockwool
| Building / requirement | PUR | PIR | Rockwool |
|---|---|---|---|
| Shed, canopy, camp unit, no fire spec | yes — cheapest | yes | over-specified |
| Warehouse < 2 000 m², no insurer requirement | yes | preferred | — |
| Warehouse with insurer / FM-style requirement | no | yes (B-s1,d0) | yes |
| Building requiring non-combustible envelope (A2) | no | no | yes |
| Fire compartment wall EI 30–120 | no | no | yes |
| Cold store / freezer | possible | yes — better λ | no (moisture) |
| Food / pharma interiors | possible | yes | yes (hygienic skins) |
| Acoustic requirement (Rw > 30 dB) | no | no | yes |
Mixed projects often use PUR on the roof and PIR or rockwool on the walls that face neighbours.
Skins, coatings and colours
| Skin | Thickness | Zinc / paint | Where |
|---|---|---|---|
| PPGI PE 25 µm | 0.40 / 0.50 / 0.60 mm | Z100–Z140, RAL 9002 / 9010 / 3009 / 7016 … | outer and inner face standard |
| PPGI SMP / PVDF | 0.50 / 0.60 mm | Z140–Z275 | coastal, Gulf, colour warranty |
| Galvanized | 0.40 / 0.50 mm | Z140–Z275, unpainted | inner face on a budget |
| Food-grade PE | 0.50 mm | Z140, RAL 9010 | food, cold-store interiors |
| Aluzinc / aluminium | 0.50 / 0.60 mm | — | to order |
Outer skin profiled (micro-rib, lined or 5-rib roof); inner skin micro-ribbed or flat.
Lengths and stock
PUR roof and wall panels 40 and 50 mm in 9002/9002 with 0.40/0.40 or 0.50/0.40 skins are made to order in 5–10 working days at any length to 14 m; 60–120 mm and other colours in 2–3 weeks. Flashings, fixings and sealants ship with the panels.
Cutting, fixing and handling
Handle and fix as for PIR panels: fine-tooth saw, self-drilling screws through skin and core into the purlin or girt, 50 mm from panel ends, openings cut on the ground and flashed, cut cores sealed with PU foam. PUR is slightly softer than PIR — use saddle washers on roof fixings and do not over-tighten. Store flat and covered; keep the film on until fixed.
Where it is used
- Sheds, warehouses and workshops without a fire specification
- Camps, site offices and prefab housing
- Agricultural buildings, poultry houses and stores
- Markets, canopies and covered yards
- Budget re-roofing and re-cladding
- Modular buildings for export projects
PUR vs PIR vs EPS
PIR costs 5 % more, insulates 10 % better and is the only foam most insurers accept; EPS is 15–20 % cheaper than PUR but needs 50 % more thickness for the same U-value. PUR sits between: the economy core for buildings where the specification is silent on fire class. For non-combustible requirements, rockwool. The overview compares all cores.
Price
PUR panels are priced per m² about 5 % below PIR on the panel list, following PPGI and polyol / isocyanate prices; the bands below are the month\'s indicative FOB Istanbul ranges for 40 and 50 mm.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
PUR panels travel like PIR: packs of 8–15 with foam separators and PE film, strapped on timber bearers and PE-wrapped, labelled with type, thickness, colours, length and count; about 400–600 m² of 50 mm panels per 40' HC, long panels on flat-racks or by covered truck to Iraq and the Caucasus. HS 7308.90 / 9406.
| Term | Detail |
|---|---|
| MOQ | 300 m² per type and thickness |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | Stock thicknesses and colours: 5–10 working days; special cores, colours and lengths 2–3 weeks |
| Packing | Panels stacked 8–15 per pack with foam separators, PE film on both faces, strapped on timber bearers, PE-wrapped |
| Container / truck | 40' HC ≈ 400–550 m² of 50 mm panels (volume-limited); 12 m panels on flat-rack or by truck to Iraq / Caucasus |
| Documents | Invoice, packing list, EN 10204 3.1 (skins), CE DoP (EN 14509), fire classification report, certificate of origin; SASO / SONCAP on request |
| Payment | 30% advance, balance against B/L copy; L/C at sight above 100 t |
Certificates
Orders ship with the CE declaration of performance under EN 14509, the core data sheet (density, λ to EN 13165), the EN 13501-1 reaction-to-fire report and the skin coil EN 10204 3.1 certificates.
How to order
Specify roof or wall panel, thickness, skins and colours, lengths and quantities, and confirm that no fire class is required (otherwise we quote PIR or rockwool); flashings, screws and destination as usual.
Standards
- EN 14509 — self-supporting double-skin metal-faced insulating panels
- EN 13501-1 fire classification; EN 13165 (PIR/PUR), EN 13162 (mineral wool), EN 13163 (EPS) cores
- EN 10169 / EN 10346 skin steel
- EN 10204 3.1
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: DX51D · S250GD · S280GD
Frequently asked questions
What is a PUR sandwich panel?
A roof or wall panel with a polyurethane foam core (λ 0.024 W/mK, 40 kg/m³) between steel skins — the classic, economical foam-core panel for sheds, camps and buildings without a fire-class requirement.
PUR or PIR — which should I buy?
PIR if any fire class, insurer requirement or cold-store use applies (5 % more); PUR for sheds, camps and buildings where the specification is silent and the budget matters.
What fire class does a PUR panel have?
Typically B-s2,d0 to B-s3,d0 to EN 13501-1 — combustible with more smoke than PIR; not accepted where B-s1,d0 or A2 is required.
What U-value does a 50 mm PUR panel have?
About 0.46 W/m²K (PIR: 0.42); 80 mm gives 0.29, 100 mm 0.23.
Is PUR the same as PU panel?
Yes — PU, PUR and polyurethane panel are the same product; PIR is the improved polyisocyanurate chemistry.