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Thermal gasket component system, allowing rainscreen applications to benefit from the low thermal conductivity values associated with aerogel insulants. Composed of a cage/ gasket and synthetic amorphous silica insulant.

Features and benefits:

  • Reduces thermal bridging in building designs - offers a high level of thermal performance at a reduced profile thickness in comparison to other insulation solutions.
  • Provides an enhanced thermal barrier between the external cladding and inner components of the assembly (which are positioned closest to the building external wall).
  • The insulant component is hydrophobic as well as being breathable and allowing vapour to pass through, helping to control corrosion under insulation.
  • Application is simple and easy, following the process of fitting standard rainscreen bracketry.


For use in rainscreen applications; specifically compatible with Nvelope and Ash & Lacy systems.


  • Satisfies sections 11 and 12 of the Centre for Window and Cladding Technology (CWCT) standards.
  • Achieves Local Authority Building Control (LABC) warranty and Premier Guarantee approval.
  • Thermal conductivity values have been UKAS accredited.
  • Hygrothermal Performance meets ETAG 004: 2013.

Standard product features


  • Material: PA66.
  • Colour: Red.
  • Reaction to fire: Small gasket exclusion.

Chi-Gasket® 021:

  • Hygrothermal performance (to ETAG 004:2013): Heat/ rain at 80 cycles and heat/ cold after 5 cycles: No visual deterioration observed.
  • Wind load testing (CWCT, section 11): No detraction to serviceability.
  • Wind safety (CWCT, section 12): Factor 1.5 x service load.


  • Thickness: 10 mm.
  • Material: Aerogel, synthetic amorphous silica.

Chi-Gasket® A2:

  • Colour: Off-white.
  • Density: 220 kg/m³.
  • Thermal conductivity (to ISO 8301:1991 and BS EN 12667:2001): 0.018 W/mK.
  • Reaction to fire (to EN 13501-1:2007): A2-s1,d0.

Chi-Gasket® 021:

  • Colour: Maroon.
  • Density: 180 kg/m³.
  • Thermal conductivity (to ISO 8301:1991 and BS EN 12667:2001): 0.021 W/mK.
  • Thermal resistance (to ISO 8301:1991 and BS EN 12667:2001): 0.494 m²K/W.
  • Reaction to fire (to BS 476-6:1989, BS 476-7:1989 and EN 13501-1:2007): Class 0/ B-s1,d0.


Product reference:

ChiGasket® A2:

Performance data when used with Nvelope brackets - consult manufacturer for details.

  • AXL-HB090D-TP: Double only. Dead load: 4.240.
  • AXL-HB090S-TP: Single only. Dead load: 1.789.
  • AXL-HB120D-TP: Double only. Dead load: 4.240.
  • AXL-HB120S-TP: Single only. Dead load: 1.342.
  • AXL-HB150D-TP: Double only. Dead load: 3.180.
  • AXL-HB150S-TP: Single only. Dead load: 1.004.
  • AXL-HB180D-TP: Double only. Dead load: 2.282.
  • AXL-HB180S-TP: Single only. Dead load: 0.665.
  • AXL-HB210D-TP: Double only. Dead load: 1.755.
  • AXL-HB210S-TP: Single only. Dead load: 0.512.
  • AXL-HB240D-TP: Double only. Dead load: 1.228.
  • AXL-HB240S-TP: Single only. Dead load: 0.359.
  • AXL-HB270D-TP: Double only. Dead load: 1.038.
  • AXL-HB300D-TP: Double only. Dead load: 0.848.
  • AXL-HBXXXD-TP: Wind suction: 5.391 kN. Wind pressure: 5.000 kN.
  • AXL-HBXXXS-TP: Wind suction: 5.044 kN. Wind pressure: 4.827 kN.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-75-40/370 Non-cellular rubber gaskets

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Euroform Products


+44 (0)1925 860999

Product reference

[Chi-Gasket® 021]
The gasket is held within a cage clipped directly to the Nvelope bracket isolator. Patented design (GB 2541513).
[Chi-Gasket® A2]
The insulant is held within a sleeve which attaches directly to the standard bracket. For use in Ash & Lacy systems.


[80 L (single)]
84.5 x 52 x 21.5 mm.
[160 L (double)]
165.5 x 52 x 23.5 mm.

Manufacturer details

Unit 2,
Lyncastle Road,
Cheshire, WA4 4SN
Tel +44 (0)1925 860999
Fax +44 (0)1925 860066
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