When should a sandwich panel have a mineral wool or PIR core?

In one area a slim wall at a given U-value may be important, while elsewhere the scope of the fire classification may govern. Identifying these needs avoids choosing a core on a single advantage or an overall material ranking.

Equal thickness does not necessarily mean equal thermal performance or comparable cost. One 100 mm PIR wall panel has U = 0.22 W/(m²K). In a particular mineral wool range, a 180 mm panel reaches a similar 0.21 W/(m²K). These figures apply to the products compared.

Thickness affects reveals, flashings and the façade line. Check available space in refurbishment. Consider the thermal data alongside load capacity, fire requirements and other conditions before choosing the slimmer option.

Wool and PIR panels have product-specific reaction-to-fire classes and fire-resistance classifications for defined assemblies. A non-combustible mineral core is significant, but the wall needs its own assessment. Evaluate PIR as part of the specified product and assembly too. The insulation name alone cannot establish suitability.

Check the required class, orientation, span and joint details. A lower U-value cannot compensate for a missed fire requirement. Compare cost and installation once both options satisfy all requirements. Wall test results cannot simply be applied to roofs or vice versa.

In this example the 100 mm PIR panel with 0.5/0.5 mm steel faces weighs about 12.3 kg/m². The 180 mm wool panel with the same facing thicknesses weighs 23.9 kg/m². Both core type and thickness contribute to the difference. Other products will have different weight ratios.

Use the weights to plan transport, lifting and structural loading. Panel length and site access matter too. For an existing hall, verify capacity for the replacement envelope. The appearance of the columns or weight of the old cladding cannot establish the structural reserve.

Use acoustic data for the actual assembly. A wool core alone will not remedy reverberation or noise through an open door. Determine whether the aim is to limit transmission, absorb sound or reduce vibration, then select the partition and any additional treatments.

For either core type, select facing finishes for humidity, chemicals and cleaning. Water-washed rooms require suitable joints and edges. Consider access for inspection and repair. Operating conditions may affect lifetime cost more than a small difference in panel price.

Different cores can be used in one building if their interface is designed. Check geometry, insulation continuity, sealing and any fire separation function. Matching colour or similar thickness does not guarantee that joint profiles engage or give the required performance.

Price each zone with its transition details, separate orders, transport and installation sequence. The final design may use one or two core types. It should define a complete enclosure whose performance can be demonstrated and inspected at handover.

Agree the appearance at system changes with the user. Different profiles can reflect light differently even in the same nominal colour. Samples and a corner drawing help predict the finished result. Coordinate the technical solution with the visible façade layout.