Select your preferred delivery date at the checkout


Contact us at: or 01509 649065 (9.00 - 17:00) Monday - Friday

Free Nationwide Shipping Available - Conditions apply
Click here for details

100% Secure Payments

90mm Celotex Thermaclass 21 Cavity Insulation -3.21m2 pack

Qty From Qty To Unit Price
1 15 £85.00
16 £82.97
Insulation Board ideal for full fill cavity wall applications leaving a 10mm residual cavity
PayPal Checkout

90mm Thermaclass Cavity Wall 21 is a 1190 x 450mm rigid polyisocyanurate (PIR) insulation solution from Celotex for masonry full fill cavity wall applications. Featuring a tongue and groove edge profile, Thermaclass Cavity Wall 21 has an excellent thermal performance of 0.021 W/m.K (“lambda 21”) which can help to achieve lower U-values without increasing the overall wall thickness. For wall constructions featuring a 10mm residual cavity, the low-emissivity foil facing increases the thermal performance in sealed cavity air spaces, improving the achievable U-value. Thermaclass Cavity Wall 21 has been assessed by the British Board of Agrément (BBA) as fit for use in defined full fill cavity wall applications if installed, used and maintained as set out in the certificate.

  • Board size: 1190 x 450mm
  • Thickness : 90mm
  • Lambda: 0.021 W/mK
  • Facer: Low emissivity foil facings
  • 6 Boards per pack
  • 3.21m2 per pack

Please contact us if you require any further information or a product data sheet.
Product Type:
PIR Insulation
Edit Product Type:
PIR Insulation
90x450x1190MM (0.535 M²)
3 - 5 working
Celotex Insulation
Product Code: