50mm Celotex CW4000 Cavity PIR Cavity Insulation Board delivers exceptional thermal efficiency with its polyisocyanurate (PIR) construction and premium low emissivity foil facing. Available in thicknesses from 40mm to 100mm, this insulation board is purpose-designed for partial fill cavity wall installations.
Celotex has discontinued the following thicknesses: 25mm, 55mm, 65mm, 70mm, 80mm and 90mm. Click to request a quotation and we will recommended an equivalent product.
Euroclass F Reaction to Fire classification, according to BS EN 13501-1. Products with this level of classification are not provided with a rating for smoke emission.
This 50mm Celotex CW4000 board achieves outstanding thermal efficiency through its 0.022 W/m.K thermal conductivity rating, allowing you to meet target U-values with minimal insulation depth.
The integrated low emissivity foil facing maximises thermal performance within sealed cavity air spaces, delivering superior U-value results compared to unfaced alternatives.
These 50mm celotex cavity insulation boards combine lightweight construction with rigid strength, ensuring simple handling and installation. Standard wall tie spacing compatibility makes fitting quick and straightforward.
This 50mm Celotex CW4000 partial fill product carries BBA certification, validating its performance for specified partial fill cavity wall applications when installed according to certificate requirements. Review the BBA certification documentation for full details and any restrictions.
When installing 50mm Celotex pir partial fill insulation, verify compliance with current Building Regulations, fire safety standards, and applicable height restrictions for your location and project type.











