Guidelines 3 - Insulation Systems / Polyisocyanurate (PIR)

Polyisocyanurate (PIR)

Insulation made of man-made materials

Polyisocyanurate (PIR) is a polymeric insulation material with the same thermal properties as PUR. Nevertheless PIR is chemically differently based on polyisocyanurate groups.

The main aim of developing PIR was to reduce hazardous risk of PUR material during fire. PIR insulation boards also emit hazardous flames during the fire, but in smaller quantities than PUR and PIR itself is not on flame but smouldering. The study by Modesti et al. (2002) shows also the development of PUR-PIR insulation material to reduce the hazardous flames during the fire hazards.

Besides the concerns connected with behaviour during fire, the concerns on PIR or PUR-PIR usage in buildings are refers to vapour impermeability of the material and the potential of moisture accumulation in building structures. This is highly relevant during the exploitation of this material in historical buildings.