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High Performance Polyisocyanurate Roof Insulation for Flat Roofs


Xtratherm FR/ALU is a Polyisocyanurate (PIR) based roof insulation with vapour & gas tight aluminium foil facings that are perfectly suited for flat roof single ply mechanically fixed membrane system installations. Xtratherm FR/ALU roof insulation boasts a thermal conductivity level as low as 0.022 W/mK and contributes towards limiting condensation within a building best suited in conjunction with a vapour control layer.

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products benefits:

0.022W/mK thermal conductivity

Vapour & gas tight foil faced

Suited for mechanically fixed single ply systems

Perfect for flat roof projects

Tech info:

  • Length


  • Width


  • Density

    32 kg/m3

  • Compressive Strength

    >150kPa @ 10% Compression

  • Thermal conductivity

    0.022 W/mK

  • U-value (80mm)


  • U-value (90mm)


  • U-value (1000mm)


  • U-value (120mm)


  • U-value (140mm)


  • Full Information:

    Check out the full
    datasheet available in
    the Downloads section!

More Info

Xtratherm FR/ALU is faced with gas-tight foil. Xtratherm FR/ALU foil faced roof boards are suitable for use below single ply mechanically fixed roof membranes. Note: FR/ALU is not suitable for applications with built-up bitumen based roofing or mastic asphalt systems.

Xtratherm FR/ALU insulation boards should be laid over the vapour control layer in break bonded pattern. The long edges of the boards should be laid at right angles to the corrugations and all board joints must be fully supported by the deck. The FR/ALU insulation boards are secured by approved mechanical fixings. The requirement for a separate water vapour control layer should be assessed in accordance with BS 6229. Typically a 1000 gauge polythene should be used with all joints lapped and sealed. Any fixings that penetrate it must be of the self sealing type that fuses to the vapour control layer during application.

Xtratherm FR/ALU foil faced insulation boards are suitable for use on roof decks that are subject to maintenance traffic. Walk ways should be provided on roofs requiring regular pedestrian access. When the roof is complete, protective boarding should be laid if additional site work is to be carried out. The completed roof should not be used for storage of heavy materials or air conditioning plant.