From;
https://www.bradfordinsulation.com.au/commercial-and-industrial-insulation/underslab/pir-boards
What is a PIR board?
Polyisocyanurate (PIR) is one of the most efficient insulation material used in construction. PIR insulation provides acoustic and thermal properties, rigidity, durability and excellent compressive strength. ... Insulation boards also referred to as loft boards, foam boards, or rigid foam.13 Feb 2020
This company offers a technical service contact
"Bradford has insulation technical experts located around Australia to assist in the correct use of these products. Please call our Bradford DesignSmart technical team on 1800 354 044 or email your enquiry to
bradforddesignsmart@csr.com.au". it may help.
BUT I NOTICE THIS IN THE SPECIFICATIONS
"• To maintain the water barrier properties of the facing material it should not be punctured, creased, crushed, sharply folded or dragged over the building structure during installation.
• Condensation Risk Consideration: The facing material is classified as a vapour barrier, and when positioned on the cold side of the construction it may increase the risk of
condensation entrapment within the structure. As there are many factors which can influence condensation risk it is highly recommended that designers undertake a
hygrothermal analysis to further reduce condensation risk"
https://insulation4less.co.uk/blogs/guides-and-news/difference-between-standard-pir-insulation-boards
Polyisocyanurate (PIR) is one of the most efficient insulation material used in construction. PIR insulation provides acoustic and thermal properties, rigidity, durability and excellent compressive strength. PIR insulation boards require approximately half the thickness of traditional forms of insulation to meet the same level of thermal performance.