Thermaclass Cavity Wall 21 is an insulation material designed for full fill masonry cavity wall applications. The boards are made up of a polyisocyanurate (PIR) core featuring a low emissivity foil facing bonded to each side which provides improved thermal performance in sealed cavity air spaces, improving the achievable U-value. Thermaclass Cavity Wall 21 is manufactured with a blowing agent that is CFC/HCFC free and has zero Ozone Depletion Potential (ODP) with a low Global Warming Potential (GWP). The board is available 1190mm by 450mm (1205mm by 465mm including tongue).
This Thermaclass product has a thickness of 140mm with a sheet coverage of 0.5355 m2. In addition to this, 140mm Thermaclass boasts an excellent thermal performance of 0.021W/mK.
- Tongue and groove edge profile
- Long lifespan
- Durable and rigid
- Easy and simple installation process
- Excellent thermal performance
- Built with the protection from weather conditions in mind
The Thermaclass boards feature a tongue and groove edge providing a continuous layer of insulation with minimal gaps to avoid thermal bridging and increase the thermal quality of the product. This also provides a protective layer against wind and rain and eliminates the need to use foil tape on board joins.
This product is light weight and easy to cut, handle, and install. The board sizes are designed to fit within cavity wall tie spacings. The boards can be cut, if necessary, by using a fine-toothed saw or scoring each side over a hard edge with a sharp blade.
The board should be stored indoors in a dry space on a flat surface. If indoor storage is not an option, weatherproofing materials should be applied to protect the boards from weather conditions. If boards get slightly wet, they should be wiped over and left to dry however if they get wet, they should not be used.
Celotex Thermaclass 140mm
Thermaclass Cavity Wall 21 should not be used in the external walls of buildings over 18 metres in height (England and Wales) or 11 metres in height (Scotland). Recent changes to Building Regulations mean that only non-combustible insulation or insulation of limited combustibility can be used in buildings of that height.
BBA approved – certificate 16/5343
Euroclass E Reaction to Fire classification, according to EN 13501-1
manufactured under Quality Management Standard – ISO 9001:2015
CE Marked (20.DOPTCCW-01) to BS EN 13165
|Thermal Conductivity (W/mK)
|Thermal Resistance (m2K/W)
|Pieces Per Pallet
Brand: Celotex Thermawall
Length: 1190mm (1205mm including tongue)
Width: 450mm (465mm including tongue)
Facings: Low emissivity foil
Thermal Conductivity: 0.021W/mK
|1190 × 450 mm
|Pieces Per Pack
Low Emissivity Foil
Celotex Thermaclass Cavity Wall Insulation