Upgrade your acoustic insulation game with the Rockwool Flexi slab 50mm — a high-performance stone wool panel engineered for framed construction in walls, floors and ceilings where space is at a premium but performance still counts. Each slab measures 1,200 mm × 600 mm with a thickness of 50 mm, and each pack covers approximately 8.64 m² (12 slabs) — offering a complete solution for acoustic and thermal improvement in one package.

What sets the Flexi version apart is the patented FLEXI Edge® along one side of each slab: designed to slot neatly into timber or metal studwork, it ensures a snug fit, reduces cutting, minimises waste and helps eliminate gaps or voids that can compromise performance. With a thermal conductivity of 0.038 W/m·K, this slab makes a strong contribution toward reducing heat loss while simultaneously improving sound insulation.

Safety matters — this product is rated Euroclass A1 (non-combustible) meaning it won’t burn, emit toxic fumes or contribute to fire spread. That makes it a solid pick for commercial builds, multi-occupancy residences and any job where fire-safety and building regulation compliance are required.

Acoustically, the semi-rigid stone wool structure is superb for absorbing airborne noise and reducing reverberation inside a cavity build-up. Whether used in a partition wall separating flats, a suspended timber floor between floors, or a ceiling structure above a home office or media room, the Flexi 50mm slab gives you a dependable performance upgrade — even when build depth is limited.

Installation is straightforward: the size fits common 600 mm stud spacings, the FLEXI Edge® helps friction-fit slabs securely between the frame, and the stone wool material is easy to score and trim, meaning faster turnaround on-site. Because it’s dimensionally stable and water-repellent, you won’t have to worry about sagging, shrinking or long-term loss of performance.

Ideal scenarios include internal stud partitions for flats/houses with noise sensitive spaces, floors between dwellings or office zones, ceilings where height is limited, and any refurbishment where you don’t have the luxury of a deep cavity but still want acoustic and thermal gains. With Rockwool’s reputation behind it and the Flexi technology ensuring better fit, you’re offering customers a premium solution — easy to sell, easy to install, and built to perform.

Key Features

• Thickness: 50 mm, for moderate cavity depths but strong performance

• Dimensions: Standard 1,200 mm × 600 mm slab size

• Pack coverage: ~8.64 m² (12 slabs per pack)

• Patented FLEXI Edge® for snug fit and minimal cutting/waste

• Thermal conductivity: 0.038 W/m·K (λD) — effective thermal insulation

• Fire rating: Euroclass A1 (non-combustible) — high safety standard

• Material: Stone wool (rock mineral wool) — durable, dimensionally stable, water-repellent

• Applications: Internal partitions, separating floors, suspended ceilings, refurbishment zones

• Easy installation: Semi-rigid slabs, friction-fit between studs/joists, minimal voids