An A1 Non-Combustible Glass Mineral Wool slab, manufactured using Knauf Insulation's unique ECOSE®...An A1 Non-Combustible Glass Mineral Wool slab, manufactured using Knauf Insulation's unique ECOSE® Technology, and is specifically designed for use as full fill insulation in masonry cavity walls. Holds an Agrement certificate by the BBA for use in all exposure zones, including those in very severe areas. Engineered to adapt to any slight imperfections in the substrate and knit together, eliminating any air gaps and preserving thermal performance for the lifetime of the building. Friction fits between wall ties, so there is no need for ancillary products, such as retaining discs or jointing tape. Full-fill solution that doesn't require cavity barriers. Full-fill glass mineral wool insulation slab, measuring 50mm in thickness, for use in masonry cavity walls. Produced with a high recycled glass content and ECOSE® Technology, it delivers strong thermal insulation while allowing vapour to pass through, supporting a healthier building fabric. A thermal conductivity of 0.035 W/mK ensures effective energy efficiency, reducing heat loss and supporting compliance with modern Building Regulations. With a Euroclass A1 non-combustible rating and full BBA certification for every UK exposure zone, it also delivers confidence in fire protection, durability, and performance over time. At 50mm thick, the slab is suited to narrow cavity widths often found in older properties and refurbishment projects, offering a practical insulation solution where space is restricted while still delivering reliable thermal and acoustic performance.
Best current price£26.99from Materials Market Trading UK Ltd
This guide is for builders, contractors, and homeowners looking to improve the thermal performance and fire safety of masonry cavity walls, particularly in older properties or refurbishment projects. The Knauf Insulation DriTherm Cavity Insulation Slab 37 - 50mm provides excellent thermal insulation and non-combustible fire protection. A key consideration is its 50mm thickness, which is ideal for narrower cavities but may require careful planning for standard or wider cavities.
All features
Model Part Number
316650
Brand
Knauf Insulation
Extended Product Information
FAQs
Is this insulation suitable for all types of walls?
This product is specifically designed for full-fill insulation in masonry cavity walls. It is not suitable for solid walls or timber frame constructions.
What does A1 non-combustible mean?
A1 is the highest European fire classification for building materials, meaning the product will not contribute to a fire and exhibits no flaming droplets.
How does ECOSE® Technology benefit the product?
ECOSE® Technology is Knauf Insulation's binder technology that uses bio-based materials, reducing the product's environmental footprint and improving indoor air quality by lowering emissions of formaldehyde and other volatile organic compounds.
Can I use this product in very exposed locations?
Yes, the product holds an Agrement certificate by the BBA for use in all UK exposure zones, including those rated as 'very severe'.
What is the U-value achieved with this insulation?
The U-value depends on the overall construction of the wall (including brickwork, plaster, and cavity width). The insulation's thermal conductivity of 0.035 W/mK contributes to achieving lower U-values, but specific calculations are needed based on the full wall build-up.
Does this insulation require a vapour barrier?
The DriTherm slab is vapour permeable, allowing moisture to pass through. In most standard masonry cavity wall applications, an additional vapour barrier is not required. However, always consult current building regulations for specific project requirements.
How thick is the slab?
This specific product variant is 50mm thick.
Troubleshooting
Slabs do not fit snugly
Ensure the cavity is clear of obstructions. If the cavity is wider than expected, additional insulation or a different product thickness may be required. For minor gaps, ensure tight butting against adjacent slabs.
Installation is difficult around services (pipes, cables)
Carefully cut the slab to fit around services, ensuring no gaps are left. Use additional small cut pieces if necessary to fill any voids completely.
Moisture noted within the cavity after installation
Check for external water ingress points (e.g., cracked render, blocked gutters). Ensure the insulation is correctly installed and that ventilation paths, if required by building regulations, are maintained. The product is vapour permeable, but excessive bulk water needs addressing.
Difficulty cutting slabs cleanly
Use a sharp, dedicated insulation knife or saw. A clean, smooth cutting action will provide the best fit.
Pros and Cons
Pros
Excellent thermal insulation reduces energy bills.
A1 non-combustible rating provides high fire safety.
Easy installation due to friction-fitting and no need for ancillary products.
Durable performance over the lifetime of the building.
Suitable for restricted cavity spaces in older buildings.
Environmentally conscious manufacturing with ECOSE® Technology.
Cons
50mm thickness may not be sufficient for all modern building regulations without supplementary insulation.
Requires careful cutting and fitting to ensure a complete fill, especially around services.
Not suitable for timber frame construction or applications requiring vapor barriers on the warm side.
Installation in very severe exposure zones requires adherence to specific BBA guidelines.
Setup, Compatibility & Care
Setup:
Ensure the cavity is clean and free from debris, old insulation, or obstructions. Remove any protruding mortar or fixings.
Measure the cavity width to confirm suitability for the 50mm slab.
Cut slabs to fit snugly between wall ties using a sharp insulation knife. Ensure a tight friction fit without compression.
Install slabs sequentially, working from the bottom upwards. Ensure each slab is butted tightly against the previous one to prevent gaps.
No additional retaining discs, fasteners, or jointing tape are typically required due to the slab's design and friction fit.
Compatibility:
Suitable for use in masonry cavity walls in all UK exposure zones.
Designed for full-fill applications in new build and refurbishment projects.
Compatible with standard masonry construction.
Care:
Store slabs flat in a dry environment, away from direct sunlight and moisture.
Handle with care to avoid excessive compression or damage.
Wear appropriate personal protective equipment (PPE) during installation, including gloves, eye protection, and a dust mask, as mineral wool can cause skin and respiratory irritation.
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