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: £128.57 (£154.28 inc VAT)
Price per m2: £47.62/m2 (£57.14 inc VAT)
- Product Code: A1-4776
- Delivery Time: up to 7 days
- Brand: Celotex (Tech. support: 01473820850)
- Model: 1190x450mm - 2.7m2
- Weight: 9.59kg
Our ratings on 25-06-2026:

4.8 out of 5
Show other thicknesses
Hide 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: 1200x2400mm - 2.88m2
Delivery Time: 1-3 working days
Celotex TB4012 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. TB4012 is also appropriate for use in floors and walls. With low emissivity foil facings, TB4012 is manufac..
Brand: Celotex
Model: 1200x2400mm - 2.88m2
Delivery Time: 1-3 working days
Celotex TB4045 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. TB4012 is also appropriate for use in floors and walls. With low emissivity foil facings, TB4012 is manufac..
Brand: Celotex
Model: 1200x2400mm - 2.88m2
Delivery Time: 1 - 5 working days
77.5mm Celotex PL4065 is a high performance thermal insulation board where the 65mm PIR insulation is bonded to 12.5mm tapered edge plasterboard. PL4000 is manufactured from rigid polyisocyanurate (PIR) using a blend of blowing agents that have zero ozone depletion potential (zero ODP) and low globa..
Guide Price: £89.54
£107.45 inc VAT
Brand: Celotex
Model: 2400x1200mm - 2.88m2
Delivery Time: 1-3 working days
90mm Celotex GA4090 is a versatile insulation board designed to address localized thermal bridge issues. With low emissivity foil facings, this board is constructed from durable polyisocyanurate (PIR) using a blend of eco-friendly blowing agents that have zero ozone depletion potential (zero ODP) an..
Guide Price: £42.89
£51.47 inc VAT
Brand: Celotex
Model: 1200x2400mm - 2.88m2
Delivery Time: 1-3 working days
Celotex TB4020 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. TB4012 is also appropriate for use in floors and walls. With low emissivity foil facings, TB4012 is manufac..
Guide Price: £54.02
£64.82 inc VAT
Brand: Celotex
Model: 1200mm x 2400mm -2.88m2
Delivery Time: 3 - 7 days
165mm Celotex XR4165 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. XR4165 is also appropriate for use in floors and walls. With low emissivity foil facings, XR4165 is m..





