Types of Sandwich Panels according to their Insulation Core: PUR, PIR, Rockwool and More

When choosing the right sandwich panel for a roof, façade or enclosure, one of the most important factors is the type of insulating core inside. The core not only defines the level of thermal or acoustic insulation, but also the fire performance, durability and weight of the panel. In this article we analyze the main types: PUR, PIR, rock wool and other materials, to help you choose the best sandwich panel insulation for your project.

1. Sandwich panel with Polyurethane (PUR) core

The PUR sandwich panel is one of the most widely used in industrial, agricultural and residential construction. Its rigid polyurethane foam core stands out for its high thermal insulation properties, even at reduced thicknesses. This makes it an energy-efficient and very popular choice for roofs and enclosures where a good indoor temperature is required in both summer and winter.

Advantages of the PUR sandwich panel:

Excellent thermal insulation.
Very light, making it easy to transport and assemble.
Very competitive price-quality ratio.

Although its fire performance is limited compared to other materials, it is still an excellent choice when the main criterion is thermal efficiency.

2. Sandwich panel with Polyisocyanurate (PIR) core.

The PIR sandwich panel is an evolution of PUR, with a similar but improved chemical structure. Its great advantage is its higher fire resistance: it achieves higher reaction-to-fire ratings without losing insulating capacity.

PIR panel characteristics:

Very good thermal insulation.
Better fire performance than PUR (classification Bs1d0 or higher).
Good dimensional stability at high temperatures.

The PIR panel has become the preferred choice for projects where fire safety is a key factor, such as industrial buildings, logistics centers or public facilities.

3. Sandwich Panel with Rock Wool Core

If the objective is to obtain excellent acoustic protection and fire resistance, the rockwool sandwich panel is the best choice. This type of panel is composed of mineral fibers arranged in layers, which provides an effective barrier against noise and heat.

Advantages of the rock wool panel:

Excellent acoustic insulation.
Maximum fire resistance (A1 classification).
Good thermal behavior.

It is very common in enclosures where sound control and safety are paramount, such as auditoriums, machine rooms, transformer stations or homes in noisy urban areas.

4. Other cores: Expanded Polystyrene (EPS) and Extruded Polystyrene (XPS).

There are also sandwich panels with EPS or XPS cores, two types of polystyrene with different characteristics. They are less common in roofing, but can be found in economical or specific solutions for certain sectors.

EPS (Expanded Polystyrene):

Acceptable thermal insulation.
More economical option.
Lightweight and easy to install.

XPS (Extruded Polystyrene):

Better moisture resistance than EPS.
Superior thermal insulation.
Something more rigid and durable.

What is the best insulation for a sandwich panel?

The choice of the best sandwich panel insulation depends on the intended use. If you need maximum thermal efficiency at low cost, PUR is ideal. If you prioritize fire performance without losing insulation, choose PIR. If your concern is noise or you work in an environment that requires certified fire resistance, rock wool is undoubtedly the best option.

Conclusion

Knowing the different types of insulation core in sandwich panels is key to making an informed decision. Whether you are designing an industrial roof, an acoustic enclosure or a prefabricated module, making the right choice between PUR, PIR or rock wool sandwich panels will ensure a durable, efficient and customized result.