Menu
Menu
Your Cart

115mm SOPREMA Thermaclass Cavity Wall 21 (previously Celotex) - Full Fill PIR Insulation - 1190mm x 450mm - pack of 5

115mm SOPREMA Thermaclass Cavity Wall 21 (previously Celotex) - Full Fill PIR Insulation - 1190mm x 450mm - pack of 5
115mm SOPREMA Thermaclass Cavity Wall 21 (previously Celotex) - Full Fill PIR Insulation - 1190mm x 450mm - pack of 5
  • Product Code: A1-7079
  • Delivery Time: 2 - 3 working days
  • Brand: Soprema
  • (Tech. support: 03300580668)
  • Model: 1190mm x 450mm - 2.7m2
Our ratings on 24-02-2026:
Google My Business Reviews
4.8 out of 5
Show other thicknesses

To get price for this product only fill below:

If you need price for more products use blue button "Add to Quote" and look for more products.

115mm SOPREMA Thermaclass Cavity Wall 21 (previously Celotex) - Full Fill PIR Insulation - 1190mm x 450mm - pack of 5

Length: 1190mm
Width: 450mm
Thickness: 115mm
Pack Quantity: 5
Board Coverage: 0.54m2
Board Coverage: 2.7m2
Thermal Conductivity: 0.021W/mK
R-Value: 5.45m2K/W
Compressive Strength: 120kPa
Fire Rating (Reaction to Fire): F

115mm SOPREMA Thermaclass Cavity Wall 21 is a high-performance, rigid polyisocyanurate (PIR) insulation board designed primarily for full fill masonry cavity wall applications. It is the flagship high-efficiency board in the Soprema range, offering a superior thermal solution for modern building envelopes.

CHARACTERISTICS

  • The board features a low thermal conductivity of 0.021 W/mK. This allows for the construction of thinner walls while still meeting or exceeding stringent thermal building regulations.
  • All four edges feature a precision-engineered tongue and groove joint. This ensures the boards lock together securely, creating a continuous insulation layer that minimises thermal bridging and prevents water tracking across the cavity.
  • While designed for full fill applications (where the insulation occupies the entire cavity), it can also be installed with a small residual cavity of up to 10mm to accommodate mortar squeeze and simplify the build process.
  • Thanks to the interlocking tongue and groove edges, there is no requirement to tape the board joints on-site, which significantly speeds up installation and reduces secondary material costs.
  • The high-quality aluminium foil facings on both sides improve the thermal performance when used in conjunction with any residual air space.

APPLICATION

  • Full Fill Masonry Cavity Walls: The primary use, where the board fills the cavity between the inner and outer leaves of a masonry wall.
  • Partial Fill Applications: Can be used with a larger residual cavity if specified by the project requirements.
  • High-Performance New Builds: Often specified for projects aiming for ultra-low U-values or superior fabric energy efficiency.

CERTIFICATION

  • BBA 24/7312 PS2/3 (UK)
  • Soprema operates independently monitored Quality and Environment Assurance Systems in line with EN ISO 9001 and EN ISO 14001.
Brand: Soprema Model: 1200mm x 2400mm - 2.88m2
Delivery Time: 2 - 3 working days
70mm SOPRATHERM GA4000 is a high-performance, rigid polyisocyanurate (PIR) insulation board. It is designed for use in multiple areas of the building envelope, providing a reliable thermal barrier for floors, walls, and roofs. SOPRATHERM GA4000 is the go-to general-purpose insulation board for a wid..
Brand: Soprema Model: 1200mm x 450mm - 5.4m2
Delivery Time: 2 - 3 working days
60mm SOPRATHERM CW4000 (previously Celotex CW4000) is a high-performance, rigid PIR insulation board specifically engineered for partial-fill masonry cavity walls. It features low-emissivity foil facings on both sides to enhance thermal performance within the cavity air space.CHARACTERISTICSWith a t..
50mm Soprema XPS SL Extruded Polystyrene Board (pack of 8) 50mm Soprema XPS SL Extruded Polystyrene Board (pack of 8)
Guide Price
Brand: Soprema Model: 1250x600mm - 6.00m2
Delivery Time: 2 - 3 working days
50mm Soprema XPS SL is an extremely durable, high strength extruded polystyrene thermal insulation board offering high water resistance for flat and pitched roofs. It can be stored and installed in severe wet weather conditions with no deterioration during its life. It is easy to cut and customise o..
Guide Price: £70.57
£84.68 inc VAT
Brand: Soprema Model: 1190mm x 450mm - 2.16m2
Delivery Time: 2 - 3 working days
140mm SOPREMA Thermaclass Cavity Wall 21 is a high-performance, rigid polyisocyanurate (PIR) insulation board designed primarily for full fill masonry cavity wall applications. It is the flagship high-efficiency board in the Soprema range, offering a superior thermal solution for modern building env..
Brand: Soprema Model: 1200mm x 2400mm - 2.88m2
Delivery Time: 2 - 3 working days
25mm SOPRATHERM TB4000 is a high-performance, rigid polyisocyanurate (PIR) insulation board designed specifically to eliminate thermal bridges. It is manufactured in very thin profiles, allowing it to fit into tight spaces such as window reveals, floor perimeters, and behind structural members where..
Brand: Soprema Model: 1200mm x 450mm - 3.78m2
Delivery Time: 2 - 3 working days
85mm SOPRATHERM CW4000 (previously Celotex CW4000) is a high-performance, rigid PIR insulation board specifically engineered for partial-fill masonry cavity walls. It features low-emissivity foil facings on both sides to enhance thermal performance within the cavity air space.CHARACTERISTICSWith a t..

Related Products

Brand: Insofast Model: ISF18A - Free Delivery
Delivery Time: 1 - 2 days
65mm Staifix Insofast Anchor is a robust one-piece metal fastener designed to securely attach drywall and insulated plasterboard panels to walls. This..
£227.87
£273.44 inc VAT
Brand: Speedline Model: 48mm x 90m
Delivery Time: 1 - 2 days
 48mm x 90m Speedline Drywall Fibreglass Tape, a flexible self-adhesive scrim tape to cover plasterboard joints...
This product is listed in the following categories and systems (click to show).