{"id":66733,"date":"2024-05-14T18:57:35","date_gmt":"2024-05-14T16:57:35","guid":{"rendered":"https:\/\/panelsandwich.org\/what-is-the-difference-between-pir-and-eps-sandwich-panels\/"},"modified":"2026-10-12T21:07:44","modified_gmt":"2026-10-12T19:07:44","slug":"what-is-the-difference-between-pir-and-eps-sandwich-panels","status":"publish","type":"post","link":"https:\/\/panelsandwich.org\/en\/what-is-the-difference-between-pir-and-eps-sandwich-panels\/","title":{"rendered":"PIR or EPS sandwich panels: differences and which to choose"},"content":{"rendered":"
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PIR sandwich panels<\/strong> provide significantly better insulation than EPS<\/strong> of the same thickness, perform much better in fire, and are more rigid and durable. EPS (expanded polystyrene) is cheaper but requires more thickness to achieve the same insulation and softens or melts with heat. For roofs, facades, and cold rooms, PIR is usually the most balanced option, while rock wool is preferred when fire safety is the top priority. <\/p>\n

What is a PIR sandwich panel<\/h2>\n

PIR (polyisocyanurate) is a rigid foam from the polyurethane family, formulated for better fire resistance. In sandwich panels, it is injected in a continuous line between two steel sheets, to which it adheres. The result is a homogeneous, joint-free core that works together with the sheets to provide rigidity and insulation. <\/p>\n

What is an EPS sandwich panel<\/h2>\n

EPS (expanded polystyrene) is manufactured by expanding polystyrene beads with steam to form blocks. To make the panel, these blocks are cut into sheets and glued to the steel plates. It is a lightweight and economical insulator, but with less insulating capacity per centimetre and poorer performance against heat than PIR. <\/p>\n

Differences between PIR and EPS<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n
Feature<\/th>\nPIR<\/th>\nEPS<\/th>\n<\/tr>\n<\/thead>\n
Thermal conductivity<\/td>\nApprox. 0.021 \u2013 0.022 W\/m\u00b7K<\/td>\nApprox. 0.035 \u2013 0.037 W\/m\u00b7K<\/td>\n<\/tr>\n
Thickness for same insulation<\/td>\n100 mm<\/td>\nApprox. 160 mm<\/td>\n<\/tr>\n
Fire performance<\/td>\nForms a charred layer that slows flame spread<\/td>\nSoftens and melts with heat<\/td>\n<\/tr>\n
Bonding with the sheet<\/td>\nContinuously injected, homogeneous core<\/td>\nCut and glued sheets<\/td>\n<\/tr>\n
Rigidity and durability<\/td>\nHigh<\/td>\nLower<\/td>\n<\/tr>\n
Price<\/td>\nHigher<\/td>\nLower<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Thermal insulation<\/h3>\n

Thermal conductivity measures how much heat a material allows to pass through: the lower the value, the better it insulates. Our panels with PUR or PIR cores have a declared conductivity of 0.0207 W\/m\u00b7K. EPS is around 0.035 \u2013 0.037 W\/m\u00b7K, meaning it lets about 70% more heat pass through at the same thickness. In practice, this translates to higher heating and cooling costs. <\/p>\n

Required thickness<\/h3>\n

To achieve the same insulation, an EPS panel must be considerably thicker: a 100 mm PIR panel insulates as much as a 160 mm EPS panel. In a facade, that means gaining about 6 cm of usable space on every wall. If you are unsure about thickness, we explain it in how thick a sandwich panel should be<\/a>. <\/p>\n

Fire Behavior<\/h3>\n

When exposed to fire, PIR forms a charred surface layer that protects the rest of the foam and slows the flame’s progress. EPS, on the other hand, starts to soften at around 80 \u2013 100\u00b0C and melts, causing the panel to lose its core quickly. <\/p>\n

Reaction to fire is classified under European standards (Euroclasses). In our panels: <\/p>\n