Minimum Order Quantity: 5 items
Unilin (formerly Xtratherm) CavityTherm is a high-performance, continuous wall insulation system offering superior thermal performance and protection from wind-driven rain.
It features a composite PIR board with a lambda value of 0.021 W/mK, designed for full-fill cavity wall applications.
The board’s gas-tight facings, bonded to a profiled HIPS skin, provide a drainage plane.
Key Features:
- Wind-driven rain protection with engineered HIPS facer
- Moisture redirected to the outer surface
- Prepositioned slots for sloping wall ties, preventing creep
- Fully engineered jointing system
- Complete accessory range for continuous insulation
- Excellent thermal bridging values
- Minimal cavity width requirement
- No engineer's report needed
- Achieves ultimate U-values and meets standards
CavityTherm delivers an efficient and practical solution, meeting A+ or Passive standards within a 100mm cavity.
It builds as a system to ensure continuous insulation and accurate installation, reducing heat loss and improving energy efficiency.
The engineered profiled facing redirects moisture, protecting against wind-driven rain.
The rebated edge detailing ensures tight interlocking, resulting in seamless continuity and excellent thermal bridging.
Bespoke ancillary pieces ensure effective insulation around services like hockey sticks, meter boxes, and corners.
For large volume orders, we may offer better delivery rates—call 0818 888 000 to discuss pricing.
Thermal conductivity: 0.021 W/m²·k (BS EN 13165:2008).
- Density 30 kg/m³
- Compressive Strength >100 kPa @ 10%
- Thermal Conductivity 0.021 W/mK
- Service Temperature -20°C to +100°C
The profile edge of CavityTherm boards allows wall ties to be positioned sloped to the outer skin and acts as a mortar template for the inner skin.
The gas-tight facings, with an additional bonded layer, create a drainage plane that directs moisture to the outer leaf.
CavityTherm’s unique profile maintains a residual channel, safeguarding the structure.
It provides U-values suitable for higher Code for Sustainable Homes levels, allowing for low carbon homes with a traditional 100mm cavity width.
Note:
Delivery of this bulky product is available Nationwide but will be subject to a bulk delivery charge.
Delivery charges are calculated during checkout according to the delivery address provided.
For larger orders, we may offer improved delivery rates.
To discuss this you can call us on 0818 888 000 for more information and confirm pricing.
Frequently asked questions:
What is CavityTherm?
Unilin (formerly Xtratherm) CavityTherm is a high-performance insulation board with a PIR core and a lambda value of 0.021 W/mK.
It features gas-tight facings and a profiled HIPS skin that channels moisture away from the insulation.
The rebated edges ensure tight interlocking during installation.
Benefits of CavityTherm
CavityTherm achieves excellent U-values, meeting Passive House standards when placed in a 150mm cavity.
It's an affordable, practical solution for low-energy designs, ensuring continuity and easy installation.
Which Wall Ties to Use?
Standard stainless steel wire wall ties, up to 5 ties per m², work well with CavityTherm.
For larger cavities or added insulation, low-conductivity ties prevent thermal bridging, maintaining a U-value around 0.15W/m²K.
Why Slope Wall Ties?
Sloping wall ties prevents water from travelling along them into the structure.
Keeping ties clean and free of mortar is essential for performance.
Available Thicknesses
CavityTherm is available in 100mm, 125mm, and 150mm cavity thicknesses, achieving U-values as low as 0.12 W/m²K.
Building Applications
Suitable for new masonry cavity walls in both domestic and non-domestic buildings up to 25m in height.
System Accessories
CavityTherm’s accessories ensure airtightness and minimize thermal bridging, addressing gaps and breaks in the insulation layer for a continuous system that meets Low Carbon Fabric standards.
Insulation Around Complex Details
Custom insulated pieces from Xtratherm prevent thermal bridging and condensation at areas like cavity trays, vents, and meter boxes.
Engineered Edge Benefits
The engineered edge detail ensures continuous insulation, complying with building regulations and avoiding penalties during U-value calculations.
Sealing Joints
When cutting boards, trim the profiled edge and tightly join the boards.
Seal joints with waterproof tape for dry surfaces or use a self-adhesive jointing strip.
Seal penetrations or repairs with tape or sealant.
What is a Cavity Board?
A cavity board is placed over installed CavityTherm boards during construction to catch mortar drops.
The HIPS skin is easy to clean with a damp cloth if necessary.
