What is EPS sandwich panel?
An EPS sandwich panel is made by gluing pre-cut expanded-polystyrene boards between two profiled steel skins with a two-component PU adhesive in a press — a discontinuous process, unlike the continuous foaming of PIR and PUR — which keeps the tooling simple and the price low. Expanded polystyrene is the white bead foam of packaging and building insulation: 15–20 kg/m³, closed-cell, λ 0.036–0.038 W/mK (about 60 % worse than PIR, so an EPS panel needs 50 % more thickness for the same U-value), light, stable, water-resistant and cheap. Its weaknesses are heat and fire: EPS softens at 75–80 °C, so it is not used behind dark roofs in hot climates without care, and untreated it burns readily (class E); the flame-retardant grade used in panels reaches B-s2,d0 / B-s3,d0 by test, but no insurer treats an EPS building as anything but combustible. Structurally the glued composite is less stiff than a foamed one — spans are 10–20 % shorter than PUR at the same thickness — and the adhesive bond, not the core, limits temperature and durability. Within those limits EPS is a good product: internal partitions and office walls inside warehouses, camp accommodation and site offices, prefab houses and schools, light roofs and walls in temperate or dry-inland climates, cold-room partitions and simple chillers where 100–150 mm of EPS matches 60–100 mm of PIR at lower cost. We produce EPS wall panels (micro-rib, lined, flat) and roof panels (5-rib) in 50–200 mm, 1 000 or 1 150 mm cover, lengths to 12 m, with 0.40–0.50 mm PPGI or galvanized skins.
Grades, standards and tolerances
| Grade / standard | Yield (MPa) | Note |
|---|---|---|
| EPS core, 15–20 kg/m³, flame-retardant (EPS-FR) | λ 0.036–0.038 W/mK | B-s2,d0 / B-s3,d0 (E untreated); EN 13163 |
| Compressive strength | ≥ 0.07–0.10 N/mm² | at 10 % deformation |
| Service temperature | −50 to +75 °C | softens above 80 °C |
| Adhesive | two-component PU | press-laminated |
| Skins DX51D + Z100–Z140 + PPGI or galvanized | ≈ 140 | EN 10346 / EN 10169 |
CE-marked to EN 14509; use flame-retardant EPS only; avoid dark outer colours in hot climates.
EPS panel thickness and U-value
| Thickness | U-value (W/m²K) | Weight (kg/m²) | Girt / purlin spacing (0.5 kN/m²) | PIR equivalent | Typical use |
|---|---|---|---|---|---|
| 50 mm | 0.68 | 8.2 | 2.6 m | 30 mm | partitions, camps |
| 60 mm | 0.57 | 8.4 | 2.9 m | 40 mm | walls, light roofs |
| 80 mm | 0.44 | 8.8 | 3.4 m | 50 mm | houses, offices |
| 100 mm | 0.35 | 9.2 | 3.8 m | 60 mm | chiller partitions |
| 120 mm | 0.30 | 9.6 | 4.1 m | 80 mm | cold rooms 0–5 °C |
| 150 mm | 0.24 | 10.2 | 4.5 m | 100 mm | cold stores |
| 200 mm | 0.18 | 11.2 | 5.0 m | 120 mm | freezer partitions |
Spans single-span L/100; EPS panels are 10–20 % less stiff than PUR at equal thickness.
Where EPS panels fit
| Application | EPS suitable? | Note |
|---|---|---|
| Internal partitions and offices in halls | yes — ideal | cheapest, light |
| Camp units, site offices, prefab housing | yes | the market standard |
| Walls of unheated / mildly heated buildings | yes | temperate and dry-inland climates |
| Roofs in hot climates (Gulf, Africa) | with care | light colours only (9002 / 9010); core softens at 80 °C |
| Cold-room partitions and simple chillers | yes | 100–150 mm; PIR for freezers |
| Buildings with fire class or insurer requirement | no | PIR or rockwool |
| Food-plant interiors | possible | sealed joints, 9010 skins |
| Fire compartment walls | no | rockwool |
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
EPS wall panels 50 and 100 mm in 9002/9002 with 0.40/0.40 skins are pressed to order in 5–10 working days at lengths to 12 m; other thicknesses (60–200 mm), roof profile, galvanized skins and colours in 2 weeks. Flashings, fixings and PU sealant ship with the panels.
Cutting, fixing and handling
Cut with a fine-tooth saw or hot-wire the core after cutting the skins; fix with self-drilling screws through the panel into girts or the camp frame, 50 mm from the ends, with washers; seal cut cores and joints with PU foam or sealant. EPS panels are light — 8–11 kg/m² — and are the easiest to handle by hand, but the glued skins must not be levered apart: lift flat, store flat, keep out of direct sun before installation (the film and the core both suffer above 60 °C).
Where it is used
- Internal partitions and offices inside halls
- Camp accommodation, site offices, guard houses
- Prefab houses, schools and clinics
- Walls and light roofs in mild and dry-inland climates
- Cold-room partitions and simple chillers
- Kiosks, containers and modular units
EPS vs PUR vs rockwool
PUR insulates 60 % better per millimetre and takes heat better for 15–20 % more; PIR adds the fire class; rockwool is the non-combustible core at twice the EPS price. EPS is right where cost rules and the building is a partition, a camp or a mild-climate shed. The overview compares the cores.
Price
EPS panels are the lowest-priced item on the panel list — per m² by thickness, about 15–20 % below PUR — following PPGI and polystyrene bead prices; the bands below are the month\'s indicative FOB Istanbul ranges for 50 and 100 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
EPS panels are stacked 10–15 per pack with foam separators and PE film, strapped on timber bearers and PE-wrapped, labelled with thickness, colours, length and count; being the lightest panel, a 40' HC still fills by volume at about 450–650 m² of 50 mm; long panels on flat-racks or by truck. Keep packs out of direct sun in transit and storage. 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 EPS core data sheet (EN 13163, flame-retardant grade), the EN 13501-1 reaction-to-fire report and the skin coil EN 10204 3.1 certificates.
How to order
Specify wall or roof panel, thickness, skins (PPGI colours or galvanized), lengths and quantities, the climate and use (so we can advise if PUR is safer), flashings and destination.
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 an EPS sandwich panel?
A wall or roof panel with a glued expanded-polystyrene core (λ 0.036 W/mK, 15–20 kg/m³) between steel skins — the cheapest insulated panel, used for partitions, camps, prefab buildings and mild-climate walls.
EPS or PUR panel?
PUR insulates 60 % better per mm, resists heat and spans further for 15–20 % more; EPS is the budget choice for partitions, camps and temperate climates. Neither is fire-rated — that needs PIR or rockwool.
Can EPS panels be used on roofs in hot climates?
Only with light colours (RAL 9002 / 9010) and ventilation — the core softens above 80 °C, which a dark roof reaches in Gulf sun.
What thickness of EPS matches 50 mm PIR?
About 80 mm; 100 mm EPS ≈ 60 mm PIR; 150 mm EPS ≈ 100 mm PIR.
Is EPS panel fire-safe?
Flame-retardant EPS panels test to B-s2,d0 / B-s3,d0 but are combustible; they are not accepted where a fire class or insurer requirement applies.