Earthwool DriTherm Cavity Slab 32 Ultimate is a high-density slab offering very high thermal resis...Earthwool DriTherm Cavity Slab 32 Ultimate is a high-density slab offering very high thermal resistance for the thermal insulation in residential and non-residential masonry cavity external walls. It holds an Agrement certificate by the BBA for use in all exposure zones, including very severe areas. Engineered to adapt to slight imperfections in the substrate and knit together, it eliminates air gaps and preserves thermal performance for the lifetime of the building. It friction fits between wall ties, so no ancillary products like retaining discs or jointing tape are needed. This is a full-fill solution that doesn't require cavity barriers. It is a full-fill glass mineral wool insulation slab, measuring 85mm in thickness, for use in masonry cavity walls. Manufactured with a high recycled glass content and ECOSE® Technology, it delivers advanced thermal insulation while remaining vapour permeable, helping the wall construction to breathe. With a thermal conductivity of 0.032 W/mK, it provides superior energy efficiency, enabling lower U-values to be achieved at reduced insulation thicknesses. Rated Euroclass A1 non-combustible and fully BBA certified for all UK exposure zones, it ensures proven fire safety, durability, and long-term reliability. At 85mm thick, the slab is suited to cavity widths that fall between traditional and modern standards, making it a practical choice for extensions, refurbishments, and new builds where non-standard dimensions are specified. This glass mineral wool slab is for full-fill masonry cavity walls. Thermal conductivity 0.032 W/mK provides enhanced insulation performance. 85mm thickness suits mid-width cavities in extensions and upgrades.
Best current price£39.56from Materials Market Trading UK Ltd
This guide is for builders, contractors, and specifiers working on residential and non-residential masonry cavity external walls. The Knauf DriTherm Cavity Slab 32 - 85mm offers a high-density solution for superior thermal resistance, ensuring excellent energy efficiency and BBA certification for all exposure zones. A potential caveat is its specific suitability for mid-width cavities, requiring careful measurement for optimal fit. Key features include high thermal resistance, full-fill capability, friction fitting, and vapour permeability.
All features
Model Part Number
715830
Brand
Knauf Insulation
Extended Product Information
FAQs
What is the thermal conductivity of the Knauf DriTherm Cavity Slab 32 - 85mm?
The thermal conductivity is 0.032 W/mK, providing high thermal resistance.
Can this insulation be used in all weather exposure zones?
Yes, it is Agrement certified by the BBA for use in all UK exposure zones, including very severe areas.
Does this product require additional fixings like retaining discs?
No, the high-density slab is designed to friction fit between wall ties, and no ancillary products like retaining discs or jointing tape are needed.
What cavity widths is the 85mm slab best suited for?
The 85mm thickness is specifically suited for cavity widths that fall between traditional and modern standards, often found in extensions and refurbishments.
Is the insulation material combustible?
No, it is rated Euroclass A1 non-combustible, ensuring a high level of fire safety.
Is the insulation vapour permeable?
Yes, it is vapour permeable, which helps the wall construction to breathe and manage moisture.
What is ECOSE® Technology?
ECOSE® Technology refers to the manufacturing process that uses a formaldehyde-free binder, resulting in a more environmentally friendly product with a high recycled glass content.
Troubleshooting
Slab does not fit snugly
Check cavity width measurements. If the cavity is slightly wider than 85mm, ensure the slab is compressed sufficiently to achieve a friction fit. If the cavity is significantly wider, consider alternative solutions or consult the manufacturer's guidelines for any permissible adaptations.
Gaps observed between slabs or at edges
Ensure slabs are installed tightly together and pushed firmly into the cavity. Minor gaps can be addressed by carefully trimming a small piece from an adjacent slab to fill the void, ensuring a continuous insulation layer.
Moisture observed on the insulation
Ensure the building envelope is weather-tight during and after installation. Protect stored slabs from rain. If moisture is present within the wall construction, identify and address the source of the water ingress separately.
Pros and Cons
Pros
Excellent thermal performance (0.032 W/mK)
Simplifies installation with friction-fit design
Suitable for all UK exposure zones
Enhances building safety with A1 non-combustible rating
Contributes to building breathability
Uses sustainable materials with high recycled content
Cons
Specific thickness (85mm) suitable for mid-width cavities only
Requires careful measurement for optimal friction fit
Not suitable for very narrow or extremely wide cavities without adaptation
Full-fill design may require specific considerations for certain building regulations regarding service penetration
Setup, Compatibility & Care
Setup:
Ensure the cavity is clean and free from debris before installation.
Measure the cavity width to confirm it is suitable for the 85mm slab.
The slabs are designed to be friction-fitted between wall ties. Install them vertically, ensuring they knit together and fill the cavity completely.
No additional retaining discs or jointing tape are required for this full-fill solution.
Compatibility:
Suitable for use in all UK exposure zones, as certified by the BBA.
Designed for full-fill masonry cavity walls.
Compatible with standard wall tie spacings.
Care:
Store slabs in a dry environment, protected from moisture and direct sunlight.
Handle with care to avoid excessive compression or damage, which could compromise the friction fit and thermal performance.
Wear appropriate personal protective equipment (PPE) during installation, including gloves, eye protection, and a dust mask.
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