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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 CavityTherm Full Fill Ext Corner Insulation PIR Board 1200 x 450 x 125mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...
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    Unilin CavityTherm Full Fill Ext Corner Insulation PIR Board 1200 x 450 x 150mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...
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    Unilin CavityTherm Full Fill Insulation PIR Board 1200 x 450 x 100mm

    CT PIR Cavitytherm is a built-in full wall insulation for traditional walls that achieves passive level U-Values as low as 0.12 W/m2K with thermal bridging detailing in cavities less than 150mm wide...
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    Unilin CavityTherm Full Fill Insulation PIR Board 1200 x 450 x 125mm

    CT PIR Cavitytherm is a built-in full wall insulation for traditional walls that achieves passive level U-Values as low as 0.12 W/m2K with thermal bridging detailing in cavities less than 150mm wide...
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    Unilin CavityTherm Full Fill Insulation PIR Board 1200 x 450 x 150mm

    CT PIR Cavitytherm is a built-in full wall insulation for traditional walls that achieves passive level U-Values as low as 0.12 W/m2K with thermal bridging detailing in cavities less than 150mm wide...
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    Unilin CavityTherm Full Fill Insulation PIR Board 1200 x 450 x 90mm

    CT PIR Cavitytherm is a built-in full wall insulation for traditional walls that achieves passive level U-Values as low as 0.12 W/m2K with thermal bridging detailing in cavities less than 150mm wide...
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    Unilin CavityTherm Full Fill Int Corner Insulation PIR Board 1200 x 450 x 100mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...
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    Unilin CavityTherm Full Fill Int Corner Insulation PIR Board 1200 x 450 x 125mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...
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    Unilin CavityTherm Full Fill Int Corner Insulation PIR Board 1200 x 450 x 150mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...
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    Unilin CavityTherm Full Fill Riser Insulation PIR Panel 1200 x 225 x 100mm

    A CavityTherm half-board that is positioned below the DPC at floor levels and allows for the recommended overlap between wall and floor insulation boosting thermal bridging performance and cutting...
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    Unilin CavityTherm Full Fill Riser Insulation PIR Panel 1200 x 225 x 125mm

    A CavityTherm half-board that is positioned below the DPC at floor levels and allows for the recommended overlap between wall and floor insulation boosting thermal bridging performance and cutting...
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    Unilin CavityTherm Full Fill Riser Insulation PIR Panel 1200 x 225 x 150mm

    A CavityTherm half-board that is positioned below the DPC at floor levels and allows for the recommended overlap between wall and floor insulation boosting thermal bridging performance and cutting...
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    Unilin CavityTherm Full Fill Top Insulation PIR Panel 1200 x 225 x 100mm

    A CavityTherm half-board that is used to finish wall insulation heights when a full board is not required, reducing cost and wastage on site.
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    Unilin CavityTherm Full Fill Top Insulation PIR Panel 1200 x 225 x 125mm

    A CavityTherm half-board that is used to finish wall insulation heights when a full board is not required, reducing cost and wastage on site.
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    Unilin CavityTherm Full Fill Top Insulation PIR Panel 1200 x 225 x 150mm

    A CavityTherm half-board that is used to finish wall insulation heights when a full board is not required, reducing cost and wastage on site.
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    Unilin CavityTherm100 Hockey Service V Insulation PIR Board 1200 x 75 x 100mm

    The Hockey service voids allows for easy access to the cable that supplies the meter box and is preformed to fit the insulation.
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    Unilin CavityTherm100 Meter Box Insulation PIR Panel 1200 x 600 x 100mm

    The preformed meter box accessory allows a recess space for placement of meter box, leaving the insulation to run in a continuous plane
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    Unilin CavityTherm125 Hockey Service V Insulation PIR Board 1200 x 75 x 125mm

    The Hockey service voids allows for easy access to the cable that supplies the meter box and is preformed to fit the insulation.
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    Unilin CavityTherm125 Meter Box Insulation PIR Panel 1200 x 600 x 125mm

    The preformed meter box accessory allows a recess space for placement of meter box, leaving the insulation to run in a continuous plane
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    Unilin CavityTherm150 Hockey Service V Insulation PIR Board 1200 x 75 x 150mm

    The Hockey service voids allows for easy access to the cable that supplies the meter box and is preformed to fit the insulation.
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    Unilin CavityTherm150 Meter Box Insulation PIR Panel 1200 x 600 x 150mm

    The preformed meter box accessory allows a recess space for placement of meter box, leaving the insulation to run in a continuous plane
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    Unilin ECO Cavity Wall Rebate Edge Insulation PIR Board 1200 x 450 x 100mm

    Partial Fill Cavity Wall Insulation Cavity Wall 360 is a bio-enhanced partial fill cavity wall insulation system. This system is designed to provide thermal performance while maintaining a residual...
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    Unilin ECO Cavity Wall Rebate Edge Insulation PIR Board 1200 x 450 x 110mm

    Partial Fill Cavity Wall Insulation Cavity Wall 360 is a bio-enhanced partial fill cavity wall insulation system. This system is designed to provide thermal performance while maintaining a residual...
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    Unilin ECO CavityTherm External Corner Insulation PIR Board 1200 x 450 x 110mm

    The CavityTherm pre-cut corner boards are designed to provide a precise and efficient solution for achieving consistent detailing at cavity wall corners. Where required, corners can also be formed on...

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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