The Rockwool HardRock Underlay Slab is a robust stone wool insulation designed to deliver exceptional thermal, acoustic, and fire performance in flat roof applications. Used in conjunction with HardRock Multi-Fix (DD), it forms a durable and non-combustible foundation layer that enhances the overall efficiency and safety of roofing systems in commercial and industrial buildings.

Benefits

• Provides a strong thermal and acoustic base layer beneath HardRock Multi-Fix (DD)
• Low thermal conductivity of 0.039 W/m·K, improving energy efficiency and comfort
• Euroclass A1 non-combustible, offering the highest level of fire safety
  
• Declared compressive strength of 70 kPa for excellent load-bearing performance
• Reduces rain noise and sound transmission through flat roof systems
• Water-repellent and dimensionally stable, maintaining long-term performance
• Manufactured from natural stone wool, supporting sustainable construction practices

Good to Know

• Designed for use in flat roof systems as a base layer with HardRock Multi-Fix (DD)
• Compatible with a wide range of flat roof build-ups, including warm roof configurations
• Easy to cut with a serrated or utility knife; wear gloves and goggles to avoid irritation
• Store under cover, off the ground, avoiding prolonged exposure to sunlight and rain
• Specialist PPE is not required, though a dust mask is recommended when cutting in unventilated areas