Mineral Wool Insulation UK – A1 Fire Rated Rockwool Slabs

Renders World offers premium mineral wool insulation UK solutions, featuring the industry-leading Rockwool Frontrock dual-density slabs. Engineered for External Wall Insulation (EWI) systems, these slabs provide the highest level of fire protection with a Euroclass A1 non-combustible rating. Unlike traditional foam-based products, our rockwool mineral slab UK range is fully breathable, making it the essential choice for timber-frame constructions, high-rise buildings, and renovation projects where moisture management and acoustic insulation are top priorities.

Advanced Dual-Density Technology

Our dual density mineral wool UK slabs are designed with a unique two-layer structure. The high-density outer surface provides a robust, impact-resistant base for rendering, while the more flexible inner layer ensures perfect adhesion to uneven masonry. With a thermal conductivity of 0.036 W/mK, Rockwool systems offer consistent thermal performance and exceptional sound absorption, creating quieter and safer living environments.

System Integration & Compatibility

To maintain the high vapour permeability of a mineral wool system, it must be installed using compatible "breathable" components. We recommend using our Roker U adhesive and basecoat, specifically formulated for stone wool fibers. For the final finish, always specify a silicone or silicate-based topcoat to ensure the system remains fully breathable and moisture-free.

• Fire Barrier: Acts as a natural stop to the spread of flames in residential blocks.
• Acoustic Performance: Significantly reduces external noise pollution compared to EPS.
• Dimensional Stability: No shrinking or expanding under extreme temperature fluctuations.
• Sustainability: Manufactured from abundant natural volcanic rock and fully recyclable.

Is Mineral Wool Right for Your Project?

• Choose this product if: Your building exceeds 11m in height, requires maximum fire safety, or you are renovating a damp-prone property that needs to breathe.
• Consider alternatives if: You are working on a low-rise domestic budget where graphite EPS boards may offer a more cost-effective U-value solution.

Frequently Asked Questions

Why is mineral wool more expensive than EPS?

The cost reflects the manufacturing process of volcanic stone and its superior fire and acoustic properties. It is often a mandatory requirement for high-rise and multi-occupancy buildings in the UK.

Do I need different fixings for Rockwool?

Yes. Due to the weight and density of mineral wool slabs, you must use high-quality mechanical fixings with a larger washer or stainless steel pins to ensure system stability.

For a detailed comparison of materials, read our expert guide: Mineral Wool vs Polystyrene UK: The 2025 Guide or contact our technical team for U-value calculations.