How do you choose the right type of sandwich panel for how the building is used?

In a small pavilion, a large glazed area and frequently opened doors can make a significant contribution to the heat balance. Panel thickness should be assessed together with these elements. The U-value of the wall alone does not determine the heating cost of the whole building.

PIR and PUR foam cores and EPS differ in their properties from mineral wool. The whole group cannot be equated with a single level of thermal conduction or fire behaviour. Within each material there are specific variants and declared parameters.

An example wall PIR panel 120 mm achieves U 0.16 W/(m²·K). The selected MW 120 mm variant has U 0.37 W/(m²·K), but a different reaction-to-fire classification. The comparison shows the trade-off between characteristics. The project requirements determine which set is useful.

The interior of a dry warehouse is gentler than a room that is regularly washed. Chemicals, water temperature and humidity matter. Check the type of facing on the inner side. The same colour does not mean the same surface resistance.

Planned washing also requires good details. Water should not reach the exposed core or accumulate in the joints. Outdoors, precipitation, soiling and the way it dries are important. Each side of the panel is assessed according to its actual environment.

In a room with a reduced temperature, it is important to limit the ingress of heat and moist air. Leakage can cause condensation or icing. A thick core helps thermally but does not replace correct joints between walls, ceiling and floor.

An example PIR cold-room panel 160 mm may have a U-value of 0.12 W/(m²·K). This does not mean a universal operating temperature for the entire cold room. A cooling load calculation, door selection and sealing details are required. The enclosure is treated as a combined system of components.

A roof panel has a different outer skin profile and water drainage details. A wall panel may have a joint with visible or concealed fixing. The choice of orientation affects the support and the rhythm of the façade. Components are not freely interchanged between applications.

Also check the spacing of the structure. A panel with a better U-value does not necessarily have a larger permissible span. Load-bearing capacity depends on the entire cross-section, the facings and the loads. The maximum length offered in production is not the distance over which a panel can hang without support.

In a structure with many doors, it is worth calculating the lintel zones and narrow strips between openings separately. They are more difficult to utilise than a full wall. Their geometry may require additional structure.

Assume a hypothetical building in Myślibórz with 70 m² of walls and 36 m² of roof. First calculate the modules and the cutting plan, and only then the rate per material. The schedule should include the number of panels, lengths and waste. Do not treat the floor area as the panel area.

Record flashings, fixings, delivery and labour as separate items. Compare two variants that meet the same requirements. For a whole series, common lengths can be optimised. Each building still requires verification of openings, structure and local conditions.

Keep the delivery markings and documents. Plan inspections of joints, flashings and drainage. Remove deposits in a manner compatible with the coating. New equipment on the wall or roof requires an assessment of the fixing. Additional weight should not be transferred to the thin sheet metal alone.

A change in the building’s function may require the building envelope to be reselected. A dry warehouse converted into a wash bay operates under different conditions. Likewise a seasonal outlet once permanent heating is installed. The material must be assessed for the current mode of use, not the building’s former name.