PIR Insulation Boards

PIR insulation boards are one of the most widely specified rigid board insulation products in UK construction. Manufactured from polyisocyanurate foam, a closed-cell thermoset material with low-emissivity foil, PIR boards deliver high thermal resistance at significantly reduced thicknesses compared to mineral wool or standard rigid board alternatives. With a thermal conductivity of 0.022 W/mK, they are a practical choice wherever strong U-value performance is needed without sacrificing usable space, whether in new build or retrofit projects across residential, commercial, and light industrial applications.

Applications for PIR Insulation Boards

PIR insulation boards are suited to floor, wall, roof, and loft applications, and the majority of products in the range carry icons confirming suitability across multiple build-up types.

Floor applications

PIR boards are installed between or beneath timber joists in suspended floor systems, or as part of a below-screed build-up in solid concrete floors. Their compressive strength and resistance to moisture make them well-suited to ground floor slabs, underfloor heating systems, and any application where boards will be subject to load or prolonged exposure to damp. The Kingspan TF70 ThermaFloor is engineered specifically for floor applications and is available across a range of thicknesses.

Roof applications

PIR is the most commonly specified rigid board insulation type in both pitched and flat roof build-ups. In pitched roofs, boards are installed between or above rafters depending on the roof design. The Kingspan TP10 ThermaPitch is a dedicated between-rafter product, while a number of general-purpose boards are also suited to above-rafter use. In flat roofs, PIR boards are used as the primary insulation layer within warm roof and cold roof configurations. An air gap is not required as a standard requirement for PIR in most flat roof applications, though ventilation strategy and condensation risk should always be assessed in line with current building regulations for the specific roof type.

Wall applications

PIR boards are used in internal stud frame systems and timber frame builds. Where a combined insulation and dry-lining solution is required, insulated plasterboard brings PIR insulation together with a plasterboard facing in a single board, simplifying installation in internal wall and dry-lining applications. For PIR-backed options specifically, the PIR insulated plasterboard range covers the leading products from the main manufacturers.

Why Choose Insulation UK for PIR Insulation Boards?

A Comprehensive PIR Range in stock across five leading brands, with thicknesses from 15mm to 200mm covering everything from slim wall upgrades to high-performance roof and floor build-ups.

Leading Manufacturers at Trade Prices including Celotex, Kingspan, Recticel, Unilin, and Ecotherm, with no minimum order value and strong stock availability across the range.

Fast UK-Wide Delivery with free shipping on orders over £500 ex VAT, dispatched from our distribution centre in Rotherham.

Half Boards Available at 25mm and 50mm, with next day delivery options for smaller orders and last-minute site requirements.

Expert Help and Advice from a team with over 50 years in the industry, on hand to help with product selection and specification across any application or build-up type.