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Celotex CW4000

Celotex CW4000

Saint-Gobain Insulation UK Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

  • QA Certificate

    QA Certificate

    Certificate type

A high performance PIR insulation board suitable for partial fill cavity wall applications.

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  • External walls - partial fill masonry cavity.

Consult manufacturer for installation details.


Celotex CW4000 is a high performance, easy to install polyisocyanurate (PIR) insulation board featuring a low emissivity foil facing. Available in thicknesses from 40-100 mm, it is suitable for use in partial fill cavity wall applications.

Product features and benefits:

  • Lightweight 1200 x 450 mm boards.
  • Squared edges.
  • Low emissivity foil facing.
  • Achieves a BRE Green Guide A rating.
  • BBA approved – certificate 16/5343.
  • Excellent thermal conductivity - decreasing the thickness of insulation required to hit the required U-value, optimizing space in the construction design and helping to reduce the heating and cooling costs within the building.
  • Low emissivity foil facing provides improved thermal performance in cavity air spaces, helping to reduce the U-value further.
  • Easy to install – lightweight boards are straightforward to handle, fit and transport. Boards are 1200 x 450 mm to fit between standard wall tie spacing.
  • BBA certification - third-party verification that the product has been assessed for its defined applications and is compliant with the relevant Building Regulations.


  • External walls - partial fill masonry cavity.

Consult manufacturer for installation details.

General information

Uniclass 2015

Pr_25_71_63_66 Polyisocyanurate (PIR) foam boardsPrimary


F30/12 Partial fill cavity insulation

F30/155 Partial fill cavity insulation

Specification data - Polyisocyanurate (PIR) foam boards

Product Reference

Celotex CW4000


40 mm

Thermal resistance (R-value): 1.80 m².K/W.

50 mm

Thermal resistance (R-value): 2.25 m².K/W.

60 mm

Thermal resistance (R-value): 2.70 m².K/W.

75 mm

Thermal resistance (R-value): 3.40 m².K/W.

85 mm

Thermal resistance (R-value): 3.85 m².K/W.

100 mm

Thermal resistance (R-value): 4.50 m².K/W.

Standard product features


Celotex CW4000 has a declared thermal conductivity of 0.022 W/m.K, according to BS EN 13165 for factory made rigid polyurethane foam (PU) products.


Euroclass E Reaction to Fire classification, according to BS EN 13501-1.


All Celotex products are manufactured under Environmental Management System – ISO 14001:2015.

BRE statements:

Achieves a BRE Green Guide rating of A. Certificate number ENP413.


All Celotex products are manufactured under Quality Management Standard – ISO 9001:2015.

Building regulations:

Helps to meet the requirements of UK thermal building regulations.


Thermal conductivity of PIR products does not change over time.

Handling, storage, health and safety:

Information regarding storage, installation and handling of Celotex products, or health and safety information, can be found on the manufacturer's website.

Third party certifications

  • BBA approved for partial fill cavity walls - Certificate Number 16/5343
  • Declaration of Performance (DoP): CE Marked to BS EN 13165 - Certificate Number 18.DOPCW4000-01
  • SGS: Manufactured under Quality Management System. BS EN ISO 9001 - Certificate Number GB91/504
  • SGS: Manufactured under Environmental Management System ISO 14001 - Certificate Number GB11/83526

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