The Rockwool Flexi 70mm slab acoustic insulation is a premium stone-wool panel engineered for dual acoustic and thermal performance in framed construction systems. With a thickness of 70mm and standard board dimensions of 1,200 mm × 600 mm, this pallet covers approximately 92.16 m² (trade bulk quantity) — ideal for large-scale installs or trade buyers.
Designed with the patented FLEXI Edge® on one long side, the product ensures a snug friction-fit between timber or metal studwork, reducing gaps, improving acoustic integrity and cutting waste from off-cuts.
It offers a thermal conductivity (λ) of approx 0.038 W/m·K, making it effective for controlling heat loss when installed in walls, floors, ceilings or separating partitions. 
The slab is rated Euroclass A1 (non-combustible) under BS EN 13501-1, giving confidence in fire safety and compliance for regulated builds. 
Acoustically, the 70mm thickness allows stronger sound separation — making it suitable for internal partitions, separating floors or ceilings, multi-residential or commercial projects where noise performance matters. The stone-wool structure retains its shape (won’t slump) even if framing shrinks.
Installation is straightforward: the Flexi 70mm slab size fits common board layouts, the FLEXI Edge ensures secure fit, and the material is dimensionally stable, water-repellent and long-lasting.
Whether you’re covering large floor plates, upgrading acoustic partitions across a building, or specifying for performance-sensitive projects — this slab is a trade-focused, spec-ready solution.

Key Features

• Thickness: 70 mm — allowing enhanced acoustic/thermal depth

• Board size: 1,200 mm × 600 mm (L×W)

• Coverage: ~92.16 m² per pallet

• Thermal conductivity: ~0.038 W/m·K

• Fire classification: Euroclass A1 (non-combustible)

• Patented FLEXI Edge® for tight fit and minimal installation gap

• Material: Stone wool (rock mineral wool) — durable, dimensionally stable, excellent for acoustic & thermal performance

• Applications: Internal partitions, separating walls/floors/ceilings, commercial/residential builds, refurbishments

• Installation: Semi-rigid slabs, easy to cut and fit, friction‐fit between studwork, reduces waste and install time