Menu
Menu
Your Cart

115mm Celotex Thermaclass Cavity Wall 21 - Rigid PIR Full Fill Cavity Insulation Board (pack of 5)

115mm Celotex Thermaclass Cavity Wall 21 - Rigid PIR Full Fill Cavity Insulation Board (pack of 5)
Guide Price
115mm Celotex Thermaclass Cavity Wall 21 - Rigid PIR Full Fill Cavity Insulation Board (pack of 5)
Guide Price: £106.25 (£127.50 inc VAT)
Price per m2: £39.35/m2 (£47.22 inc VAT)
  • Product Code: A1-4776
  • Delivery Time: up to 7 days
  • Brand: Celotex
  • (Tech. support: 01473820850)
  • Model and Size: 1190x450mm - 2.7m2
  • Weight: 9.59kg
Our ratings on 08-10-2025:
Google My Business Reviews
4.8 out of 5
Show other thicknesses

115mm Celotex Thermaclass Cavity Wall 21 - Rigid PIR Full Fill Cavity Insulation Board (pack of 5)

Width: 450mm
Length: 1190mm
Pack Coverage: 2.7m2
Pack Quantity: 5
Weight/m2: 3.55kg
Weight: 9.59kg
Thermal Conductivity: 0.021W/mK
R-Value: 5.45m2K/W
Fire Rating (Reaction to Fire): E

115mm Celotex Thermaclass Cavity Wall 21 is a high performance rigid PIR full fill cavity insulation board with low emissivity foil facings offering enhanced thermal performance (0.021 W/m.K) within cavity air spaces. It can be installed with up to a 10mm residual cavity or as a full fill solution with no residual cavity. Celotex Thermaclass Cavity Wall 21 is manufactured from rigid polyisocyanurate (PIR) using a blend of blowing agents that have zero ozone depletion potential (zero ODP) and low global warming potential (GWP).

APPLICATION

  • Full fill cavity insulation,
  • Can be installed with up to a 10mm residual cavity

CHARACTERISTICS
  • Excellent thermal performance, 
  • Lightweight and easy to install,
  • Tongue and groove for easy installation,
  • The boards are sized to fit standard cavity wall tie spacing,
  • Can be used up to 18 metres height (England and Wales),
  • Includes low emissivity foil facings giving improved thermal insulation performance within cavity air spaces,
  • Has excellent dimensional stability,
  • Provides reliable long term energy savings for buildings.
CERTIFICATION
  • BBA certified, 
  • Euroclass E Reaction to Fire classification, according to BS EN 13501-1,
  • Manufactured under Environmental Management System ISO 14001:2015,
Brand: Celotex Model and Size: 1200 x 450mm - 4.86m2 55mm
Delivery Time: 1 - 5 working days
55mm Celotex CW4000 is an insulation board aimed specifically at partial fill cavity wall applications. It comprises a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022 W/mK and low emissivity aluminium foil facings on both sides. CW4000 is manufactured from rigid pol..
Get Best Price
Brand: Celotex Model and Size: TD4000- 2400 x 1200
Delivery Time: 1 - 5 working days
Celotex TD4000 comprises a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022 W/mK, and low emissivity aluminium foil facings on both sides bonded to a layer of 5.5mm WBP exterior grade plywood.APPLICATIONCelotex TD4000 is purpose designed for use in light traffic..
Get Best Price
Brand: Celotex Model and Size: 1200x2400mm -17.28m2
Delivery Time: 5 - 7 days
Celotex XR4200 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. XR4200 is also appropriate for use in floors and walls. With low emissivity foil facings, XR4200 is ma..
£582.03
£698.44 inc VAT
Add to Cart
Brand: Celotex Model and Size: 1200x2400mm - 51.84m2
Delivery Time: Out Of Stock
125mm Celotex FI5000 is a premium flooring insulation board with enhanced thermal performance as well as an A rating when compared to the BRE Green Guide and an innovative cement compatible composite facer with a built-in vapour control layer (VCL), enabling direct screed, without the need for an ad..
Get Best Price
Brand: Celotex Model and Size: 2400x1200mm - 2.88m2
Delivery Time: 1-3 working days
Celotex XR4120 is targeted at cut-to-fit applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation than has previously been possible. XR4120 is also appropriate for use in floors and walls. With low emissivity foil facings, XR4120 is ma..
£51.70
£62.04 inc VAT
Add to Cart
Brand: Celotex Model and Size: 2400x1200mm - 2.88m2
Delivery Time: 1-3 working days
50mm Celotex GA4050 is a multi-purpose insulation board that provides a solution to overcome localized thermal bridges. Featuring a low emissivity foil facings, this board has been manufactured from tough polyisocyanurate (PIR) using a perfect mix of certain blowing agents which have zero ozone depl..
£21.93
£26.32 inc VAT
Add to Cart
This product is listed in the following categories and systems (click to show).