Knauf 125mm DriTherm 32 Cavity Wall Insulation Slab Pack of 4 (2.18m²)
Knauf 125mm DriTherm 32 Cavity Wall Insulation Slab is a high-performance glass mineral wool insulation designed specifically for external full-fill masonry cavity walls. With a declared thermal conductivity of just 0.032 W/mK, DriTherm Cavity Slab 32 provides excellent thermal performance while offering the flexible, close-fitting installation characteristics of mineral wool insulation.
Each pack contains 4 slabs measuring 1200x455x125mm and provides approximately 2.18m² of coverage. At 125mm thickness, the insulation delivers a thermal resistance of 3.90m²K/W and achieves Euroclass A1 reaction-to-fire classification, meaning it is non-combustible.
The semi-rigid glass mineral wool slabs are designed to friction fit between wall ties and knit closely together, helping accommodate minor imperfections in masonry surfaces and minimise unintended gaps within the insulation layer.
Key Features & Benefits - Knauf 125mm DriTherm 32 Cavity Wall Insulation Slab
- Manufacturer: Knauf Insulation
- Range: DriTherm® Cavity Slab 32
- Product type: Cavity wall insulation slab
- Material: Glass Mineral Wool
- Thickness: 125mm
- Slab size: 1200x455x125mm
- Pack quantity: 4 slabs
- Coverage: approximately 2.18m² per pack
- Thermal conductivity: 0.032 W/mK
- Thermal resistance: 3.90m²K/W
- Reaction to fire: Euroclass A1 - non-combustible
- Application: External full-fill masonry cavity walls
- Water resistance: Manufactured with a water-repellent additive
- BBA Agrément: 95/3212
- Technology: ECOSE® Technology
- Manufacturer product code: 715828
- EAN / GTIN: 5056376642196
- Packs per pallet: 40
- Designed to friction fit between wall ties
- Flexible mineral wool helps adapt to minor irregularities in masonry
- Closely fitting slabs help minimise air gaps within the insulation layer
- High-performance 0.032 W/mK cavity wall insulation
125mm Cavity Wall Insulation
Knauf DriTherm Cavity Slab 32 is designed for suitable external masonry cavity walls where full-fill mineral wool insulation forms part of the specified wall construction.
The 125mm thickness is suitable for projects where the cavity and thermal design require a 125mm insulation layer. The cavity should be designed to accommodate the specified insulation thickness rather than compressing a thicker slab into a narrower space.
High Thermal Performance - 0.032 W/mK
DriTherm Cavity Slab 32 has a declared thermal conductivity of 0.032 W/mK, providing excellent thermal performance for masonry cavity wall construction.
At 125mm thickness, the slab provides a thermal resistance of 3.90m²K/W.
The overall U-value of the completed wall will depend on the complete construction, including the inner and outer masonry leaves, block specification, wall ties, finishes and other materials.
Designed for Full-Fill Masonry Cavity Walls
Knauf DriTherm Cavity Slabs are specifically designed for use as full-fill insulation within suitable external masonry cavity walls.
When correctly installed, the mineral wool provides a continuous insulation layer between the inner and outer masonry leaves, helping reduce heat loss through the external wall construction.
The correct DriTherm thickness should always be selected according to cavity width, required thermal performance, exposure conditions and the project specification.
Designed to Fit Between Wall Ties
Each DriTherm slab is manufactured at 455mm wide to work effectively with standard vertical wall-tie spacings.
The semi-rigid mineral wool friction fits around the wall ties and allows adjacent slabs to be closely butted together.
Knauf states that this friction-fit installation means ancillary retaining discs or jointing tape are not required when the product is installed as specified.
Flexible Mineral Wool Helps Reduce Gaps
Glass mineral wool can adapt to slight imperfections in masonry surfaces and surrounding construction.
The fibres allow neighbouring slabs to knit closely together, helping minimise unwanted air gaps which could otherwise reduce the thermal performance of the cavity insulation layer.
Water-Repellent Cavity Wall Insulation
Knauf DriTherm Cavity Slabs are manufactured with a water-repellent additive to help resist moisture ingress within suitable masonry cavity wall systems.
The insulation should still be correctly stored, handled and protected during construction. Avoid installing damaged or heavily contaminated slabs and protect unfinished wall sections against unnecessary weather exposure.
BBA Certified for Cavity Wall Applications
DriTherm Cavity Slabs hold BBA Agrément certification for use in suitable masonry cavity wall constructions.
Knauf states that the system is approved for use in all exposure zones, including very severe exposure areas, when the wall design and installation comply with the requirements of the relevant BBA certificate.
Building height, exposure conditions, masonry type, cavity width and other project-specific requirements should always be checked before installation.
Ideal for New Builds & Extensions
Knauf 125mm DriTherm 32 is suitable for a wide range of masonry cavity wall construction projects where this thickness and thermal specification meet the design requirements.
Typical applications include:
- New-build houses
- House extensions
- External masonry cavity walls
- Residential developments
- Suitable non-domestic masonry construction
- Projects requiring high-performance full-fill cavity insulation
Euroclass A1 Non-Combustible Insulation
Knauf DriTherm Cavity Slab 32 achieves a Euroclass A1 reaction-to-fire classification in accordance with EN 13501-1.
A1 is the highest Euroclass reaction-to-fire classification and means the glass mineral wool insulation is classified as non-combustible.
Pack of 4 - 2.18m² Coverage
Each pack contains 4 individual DriTherm cavity insulation slabs, with each slab measuring 1200x455x125mm.
The complete pack provides approximately 2.18m² of insulation coverage.
When calculating the number of packs required, use the actual insulated wall area and allow appropriately for openings, detailing, cutting and project-specific wastage.
ECOSE® Technology
Knauf DriTherm Cavity Slab 32 is manufactured using ECOSE® Technology, Knauf Insulation's plant-based binder technology used within its glass mineral wool insulation range.
This technology gives Knauf glass mineral wool its distinctive natural brown appearance and forms part of the manufacturer's current insulation system.
Durable Cavity Wall Insulation
DriTherm Cavity Slabs are designed to provide long-term thermal performance when correctly installed and protected within the cavity wall construction.
The close-fitting mineral wool helps maintain a continuous layer of insulation while adapting to small irregularities within the masonry construction.
Installation Advice
Install DriTherm Cavity Slabs as the masonry wall is constructed, positioning the insulation closely between the wall ties and tightly butting neighbouring slabs together.
Avoid unnecessary gaps and keep the cavity clear of excessive mortar droppings or other construction debris.
The 125mm slabs should not be compressed into a cavity narrower than their specified thickness.
Protect exposed insulation and unfinished cavity walls from adverse weather during construction and always follow Knauf Insulation's current installation guidance, BBA certification and the project specification.
Knauf DriTherm Cavity Slab Technical Information
For complete manufacturer information covering thermal performance, available thicknesses, BBA certification, installation requirements and product applications, refer to the current Knauf Insulation DriTherm Cavity Slabs technical datasheet and installation guidance.
DriTherm 32 Thermal Performance
The number in the DriTherm 32 product name relates to its declared thermal conductivity of 0.032 W/mK.
At the same insulation thickness, a lower thermal conductivity provides greater thermal resistance than a product with a higher lambda value.
The appropriate DriTherm grade and thickness should therefore be selected according to the required wall U-value, cavity width and complete construction specification.
Why Choose Knauf 125mm DriTherm 32 Cavity Wall Insulation Slab?
Knauf 125mm DriTherm 32 Cavity Wall Insulation Slab combines high thermal performance with the practical installation benefits of semi-rigid glass mineral wool. Its 0.032 W/mK thermal conductivity, 3.90m²K/W thermal resistance, water-repellent construction and Euroclass A1 non-combustible classification make it a strong choice for thermally efficient external masonry cavity walls.
With 4 slabs per pack covering approximately 2.18m², the 125mm DriTherm 32 slab provides a practical full-fill cavity insulation solution where a 125mm insulation thickness meets the requirements of the wall design.
