PIR sandwich panels vs mineral wool - which solution to choose?

 

Comparison of the two most important insulation technologies

In industrial and commercial construction, the most common choices are PIR sandwich panels and mineral wool boards. Both solutions have their own unique properties and applications. In this article, we provide a detailed technical comparison to help you make the best decision for your project.

PIR sandwich panels - highest energy efficiency

Sandwich panels with PIR (polyisocyanurate) core is currently the most technologically advanced insulation solution in construction.

PIR technical features:

  • Thermal conductivity coefficient λ0.021-0.022 W/mK
  • Fire resistance: Reaction to fire class B-s1,d0
  • Moisture resistance: Very good - closed cell structure
  • Operating temperature rangefrom -40°C to +120°C
  • Compressive strength: 150-200 kPa

Key benefits of PIR panels:

Best thermal insulation - The lowest lambda coefficient of all available insulation materials means maximum energy efficiency with minimum panel thickness.

Excellent fire resistance - PIR has very good fire properties among organic materials. In contact with fire, it forms a stable carbon layer that slows the spread of flames.

Dimensional stability - The material does not shrink or expand significantly due to temperature changes, ensuring that the joints last and the partitions remain airtight for decades.

Moisture resistance - The closed cell structure of PIR means that the material absorbs virtually no water, eliminating problems with degradation of insulation properties.

Chemical resistance - PIR is resistant to most chemicals, oils and solvents, which is key in industrial applications.

PIR board applications:

  • Industrial halls and high-bay warehouses
  • Facilities with high energy requirements
  • Buildings in severe climate zones
  • Refrigeration and freezer structures
  • Facilities with increased fire requirements
  • Passive and low-energy buildings

Composite panels with mineral wool - superior fire resistance

Sandwich panels with mineral wool core is the solution for buildings with the highest fire and acoustic requirements.

Technical properties of mineral wool:

  • Thermal conductivity coefficient λ0.039-0.042 W/mK
  • Fire resistance: Reaction to fire class A2-s1,d0 (non-combustible material)
  • Moisture resistance: Requires moisture protection
  • Operating temperature rangefrom -40°C to +200°C
  • Melting point: Above 1000°C
  • Compressive strength: 40-80 kPa

Key benefits of mineral wool panels:

Highest fire resistance - Mineral wool is a completely non-flammable material that not only does not propagate fire, but can serve as an effective fire barrier. It retains structural integrity at fire temperatures.

Excellent sound insulation - The fibre structure of mineral wool provides exceptional sound-absorbing properties, making it ideal for buildings requiring noise control.

Vapour permeability - The material allows natural vapour diffusion through the envelope, which can be beneficial in some architectural applications.

Resistance to very high temperatures - Mineral wool retains its insulating properties even at extremely high temperatures, far exceeding those of organic materials.

Pest resistance - The inorganic material does not provide food for rodents, insects or micro-organisms.

Chemical stability - Mineral wool is chemically inert and does not react with most building substances.

Mineral wool board applications:

  • Facilities with the highest fire requirements
  • Public buildings (schools, hospitals, offices)
  • High temperature industrial installations
  • Facilities requiring acoustic insulation
  • Tall buildings over 25 metres
  • Fire zones and stairwells

Detailed comparison of properties

Energy efficiency

PIR offers significantly better thermal insulation. To achieve the same thermal resistance value of R=5.0 m²K/W, you need:

  • PIR: 11-12.5 cm thick
  • Mineral wool: 18.5-21 cm thick

This difference is fundamental to the design of structures and the thickness of partitions.

Fire safety

Mineral wool has a clear advantage in fire resistance:

  • Class A2-s1,d0 (non-combustible) vs B-s1,d0 (flame-retardant)
  • No emission of toxic gases during a fire
  • Maintaining structural integrity at high temperatures
  • Can be used as a fire barrier

Mechanical properties

PIR is characterised by a higher mechanical strength:

  • 3-5 times higher compressive strength
  • Improved resistance to mechanical damage
  • Dimensional stability over a wide temperature range

Resistance to environmental conditions

PIR shows better resistance to:

  • Effect of moisture (absorbability practically zero)
  • Freeze-thaw cycles
  • Effects of chemicals

Mineral wool requires additional protection from moisture, but offers:

  • Vapour permeability
  • UV and ageing resistance
  • Resistance to extreme temperatures

Acoustic properties

Mineral wool far outperforms PIR in sound attenuation:

  • Sound absorption coefficient αw up to 1.0
  • Excellent damping of sounds of different frequencies
  • Ideal for facilities requiring acoustic comfort

When to choose PIR and when to choose mineral wool?

Select PIR when:

  • Maximum energy efficiency is a priority
  • Minimum partition thickness is important
  • The facility is exposed to moisture
  • High mechanical strength is needed
  • You are building refrigeration or freezer structures
  • You are implementing projects in difficult climatic conditions

Choose mineral wool when:

  • Highest fire resistance is paramount
  • You are building a public or strategically important facility
  • Sound-absorbing properties required
  • Facility requires vapour permeable partitions
  • You are planning a high temperature application (above 120°C)
  • You are developing a high-rise building

Hybrid solutions - the best of both worlds

In some projects it is worth considering use of both materials in different parts of the building:

  • PIR in the building envelope for maximum energy efficiency
  • Mineral wool in fire zones and high risk areas
  • PIR in areas exposed to moisture
  • Mineral wool in areas requiring sound insulation

Conclusions - informed choice based on priorities

Both PIR sandwich panelsas well as mineral wool boards are excellent technical solutions, but they serve different purposes. PIR dominates where energy efficiency and environmental resilience are key, while mineral wool remains indispensable in applications requiring the highest levels of fire safety and acoustic control.

The final choice should result from an analysis of the specific requirements of the project, legal standards and the long-term needs of the building's use. Our specialists at Izopanel will help you choose the optimal solution - contact our team to receive a professional technical consultation tailored to your project.