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PIR Insulation Board

PIR insulation, also called Polyisocyanurate or PIR board, is a high-performance, rigid foam insulation with excellent thermal conductivity. It is moisture resistant and offers strong fire resistance. Suitable for lofts, floors, and walls, PIR board is space-saving thanks to its thin design. Our range of PIR insulation includes various sizes from Unilin.

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    Unilin Thin-R Plus Hyfloor Insulation PIR Board T&G 2400 x 1200 x 125mm

    An unbeatable choice in all thermal insulation, Hyfloor (T&G) has a superior thickness to performance ratio allowing the lower targets required under Building Regulations. XT/HYF (T&G) tongue and groove jointing offers a practical on-site solution that...
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    Unilin Thin-R Plus Hyfloor Insulation PIR Board T&G 2400 x 1200 x 150mm

    An unbeatable choice in all thermal insulation, Hyfloor (T&G) has a superior thickness to performance ratio allowing the lower targets required under Building Regulations. XT/HYF (T&G) tongue and groove jointing offers a practical on-site solution that...
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    Unilin Thin-R Plus Hyfloor Insulation PIR Board T&G 2400 x 1200 x 75mm

    An unbeatable choice in all thermal insulation, Hyfloor (T&G) has a superior thickness to performance ratio allowing the lower targets required under Building Regulations. XT/HYF (T&G) tongue and groove jointing offers a practical on-site solution that...
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    Unilin Thin-R Polyiso Strips Insulation PIR Board 1200 x 100 x 25mm

    Unilin / Xtratherm Thin-R XT/STR is a CFC/HCFC free, rigid polyisocyanurate (PIR) core faced each side with low emissivity foil. Pre-cut to minimise thermabridging at floor and wall junctions, thanks to its unique gasketed lap joint system which...
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    Unilin Thin-R Polyiso Strips Insulation PIR Board 1200 x 150 x 25mm

    Unilin / Xtratherm Thin-R XT/STR is a CFC/HCFC free, rigid polyisocyanurate (PIR) core faced each side with low emissivity foil. Pre-cut to minimise thermabridging at floor and wall junctions, thanks to its unique gasketed lap joint system which...
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    Unilin Thin-R Polyiso Strips Insulation PIR Board 1200 x 200 x 25mm

    Unilin / Xtratherm Thin-R XT/STR is a CFC/HCFC free, rigid polyisocyanurate (PIR) core faced each side with low emissivity foil. Pre-cut to minimise thermabridging at floor and wall junctions, thanks to its unique gasketed lap joint system which...
  • XTUF_Strip.png

    Unilin Thin-R Polyiso Strips Insulation PIR Board 1200 x 250 x 25mm

    Unilin / Xtratherm Thin-R XT/STR is a CFC/HCFC free, rigid polyisocyanurate (PIR) core faced each side with low emissivity foil. Pre-cut to minimise thermabridging at floor and wall junctions, thanks to its unique gasketed lap joint system which...
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    Unilin XT Thermal Liner DD Insulation PIR Board 2400 x 1200 x 50.5mm

    Unilin / Xtratherm XT Thermal Liner is specifically designed to create a thermal break in the building envelope and provide a maximum level of insulation with minimal acoustic impact. It is perfectly suited to modern constructions projects where high...
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    Unilin XT Thermal Liner DD Insulation PIR Board 2400 x 1200 x 52.5mm

    Unilin / Xtratherm XT Thermal Liner is specifically designed to create a thermal break in the building envelope and provide a maximum level of insulation with minimal acoustic impact. It is perfectly suited to modern constructions projects where high...
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    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 32.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
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    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 37.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
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    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 50.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
  • XTTLMF.png

    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 52.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
  • XTTLMF.png

    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 62.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
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    Unilin XT Thermal Liner MF Insulation PIR Board 2400 x 1200 x 72.5mm

    Unilin / Xtatherm XT Thermal Liner MF Insulation PIR Board is a composite insulated panel of Xtratherm PIR insulation core with a composite foil facing bonded to 12.5mm tapered edge plasterboard for internal walls, sloped roofs and ceilings. XT/TL-MF is...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board 1200 x 450 x 100mm

    XO/CW is an innovative partial fill cavity wall insulation system incorporating robust facings, engineered jointing details, preformed corners and a certified lambda of 0.021 W/mK. This lower lambda improves U-Values and meets Zero Carbon standards,...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board 1200 x 450 x 75mm

    XO/CW is an innovative partial fill cavity wall insulation system incorporating robust facings, engineered jointing details, preformed corners and a certified lambda of 0.021 W/mK. This lower lambda improves U-Values and meets Zero Carbon standards,...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board 1200 x 450 x 80mm

    XO/CW is an innovative partial fill cavity wall insulation system incorporating robust facings, engineered jointing details, preformed corners and a certified lambda of 0.021 W/mK. This lower lambda improves U-Values and meets Zero Carbon standards,...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board T&G 1200 x 450 x 100mm

    XtroLiner is an innovative partial fill wall cavity insulation system incorporating robust facings and preformed corners. The XO/CW jointing offers a practical on-site solution that results in a more robust continuous layer of insulation, minimising the...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board T&G 1200 x 450 x 60mm

    XtroLiner is an innovative partial fill wall cavity insulation system incorporating robust facings and preformed corners. The XO/CW jointing offers a practical on-site solution that results in a more robust continuous layer of insulation, minimising the...
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    Unilin XtroLiner Cavity Wall Insulation PIR Board T&G 1200 x 450 x 80mm

    XtroLiner is an innovative partial fill wall cavity insulation system incorporating robust facings and preformed corners. The XO/CW jointing offers a practical on-site solution that results in a more robust continuous layer of insulation, minimising the...
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    Unilin XtroLiner Framing Insulation PIR Board 2400 x 1200 x 100mm

    XtroLiner XO/FB is a PIR foamboard which has been specifically developed for use as a thermally efficient insulation board in building constructions. XO/FB is designed for use in a wide range of construction including steel or timber frame applications...
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    Unilin XtroLiner Framing Insulation PIR Board 2400 x 1200 x 30mm

    XtroLiner XO/FB is a PIR foamboard which has been specifically developed for use as a thermally efficient insulation board in building constructions. XO/FB is designed for use in a wide range of construction including steel or timber frame applications...
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    Unilin XtroLiner Framing Insulation PIR Board 2400 x 1200 x 40mm

    XtroLiner XO/FB is a PIR foamboard which has been specifically developed for use as a thermally efficient insulation board in building constructions. XO/FB is designed for use in a wide range of construction including steel or timber frame applications...

PIR Insulation Board

What are PIR boards?

PIR stands for Polyisocyanurate — a rigid type of thermal insulation made from plastic foam.

First introduced in the 1960s as an upgrade to PUR (Polyurethane) boards, PIR offers better insulation performance and versatility.

Where can PIR Insulation be used?

  • Walls – Products like Ecoliner are ideal for insulating and drylining internal walls. Eco-Versal suits timber frame walls, with both sides faced in aluminium foil for improved efficiency. As the name suggests, Eco Cavity is designed for cavity or masonry walls and fits standard brick and block dimensions.
  • Flooring – Works with most flooring types, including timber, solid concrete, and suspended floors. Insulating floors helps prevent heat loss and keeps interiors warmer.
  • Lofts – Loft spaces are one of the most common areas for heat loss. Using PIR or PUR insulation can improve energy efficiency and reduce heating costs.
  • Eco-Versal versatility – A popular PIR option that works across pitched roofs, walls, loft ceilings, and floors for consistent thermal performance throughout the home.

Frequently Asked Questions

What is pir insulation?
Polyisocyanurate (PIR) is one of the most efficient insulation materials used in construction. Pir insulation boards are typically available in the following sizes: 25mm, 75mm, 100mm, 120mm and 150mm.
What does pir stand for in pir insulation?
Polyisocyanurate, also referred to as PIR, is a thermoset plastic typically produced as a foam and used as rigid thermal insulation.
Is pir insulation flammable?
Whilst we urge you to refer to the manufacturer’s fire testing certifications, commercially available PIR insulation is not typically flammable.
Is pir insulation waterproof?
While PIR insulation boards are generally resistant to moisture, they are not fully waterproof.
What is the difference between pir and phenolic insulation?
As with the PIR/PUR boards above, phenolic insulation boards also have a closed cell structure. Phenolic board has a slightly higher r-value (higher is better, unlike u-values) and a slightly thinner profile than PIR/PUR boards due to the manufacturing process.

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