Full Fill Built-in Insulation System Continuous wall insulation system that delivers ultimate thermal performance with the added assurance of protection from wind driven rain.

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Xtratherm offer an extensive range of technically enhanced rigid insulation products for commercial and industrial projects

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Tapered Roofing System
The XtraFall system provides a high performance precision solution to thermal insulation and water drainage on at roofs.

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The Xtratherm range of high performance insulation boards provides the ideal technically advanced solution for flat roof projects.

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Developers and their design and certification team can rely on the expertise and professional support of the whole Xtratherm Team - it is not just about buying insulation products.

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PLATINUM SERVICE for Self Builders

PLATINUM SERVICE for Self Builders

Our Platinum Service offers full technical support and advice, helping you to achieve a cost effective, passive
standard new home.

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Full Fill Built-in Insulation System

Continuous wall insulation system that delivers ultimate thermal performance
with the added assurance of protection from wind driven rain.

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High Performance rigid extruded polystryrene


Xtratherm offers a cost effective solution for builders and specifiers for the closing of cavities around window and door openings, preventing cold bridging, damp penetration, air infiltration and condensation.

CavityTherm Accessories

detailing accessories

PIR Insulation


Built-in Full Fill Wall

Applications:Wall / Full



CavityTherm Flex is the perfect solution when insulating fair faced inner block walls or when block is laid flat resulting in an uneven surface to accept the insulation. The 25mm flexible fleece layer absorbs any variations due to block tolerances, providing a continuous unbroken bond between insulation layer and block. Passive level U-Values as low as 0.14 W/m²K with excellent thermal bridging detailing in cavities less than 150mm wide.

CavityTherm Flex (Inner block 215)

Block Type 125mm 150mm
Light 0.15 0.14 0.12
Med 0.33 0.16 0.13
Dense 1.15 0.17 0.14

CavityTherm Flex (Inner Block 100)

Block Type 125mm 150mm
Light 0.15 0.16 0.13
Med 0.33 0.16 0.14
Dense 1.15 0.17 0.14

Property & Units

CavityTherm Flex

Length (mm) 1200
Width 450
Thickness (mm) 125 150
Typical R-Value * 5.50 6.70
*PIR+Flexible Fleece

Product Downloads

Product Range

CavityTherm provides a ‘system’ that delivers on U-values, is practical, and with a full range of innovative detailing accessories – it delivers on continuity.

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Key Points

  • Engineered HIPs facer provides wind driven rain protection
  • Moisture redirected to outer surface
  • Flexible backing to eliminate indentations
  • Prepositioned slots for sloping wall ties
  • Fully engineered jointing
  • Full range of accessory pieces build continuous system
  • Excellent Thermal Bridging Values

Xtratherm reserves the right to change this information without notice.
Xtratherm accepts no responsibility for errors or omissions on the website.

Do you have any questions?

Talk to the team who can help you with your project

Our Technical Team provides technical services throughout our customer bases in Ireland & UK. Their experience and expertise has been built through our engagement and participation with the Irish construction industry for over 30 years.

Certified Technical Knowledge.

Solutions you can trust.

Call The Technical Team:
Tel +44 (0) 371 222 1055
Tel +353 (0) 46 906 6050

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