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Rockwool Acoustic Insulation

Buy Rockwool insulation online at ex-VAT trade prices. Rockwool stone wool is non-combustible (Euroclass A1) and a go-to for acoustic partitions, separating floors and timber or steel frame walls.

What we stock

  • Rockwool RWA45 acoustic slab: 1200 × 600mm, 50, 75 and 100mm, from £25.18 a pack, for sound insulation in stud partitions, floors and ceilings.
  • Rockwool Flexi slab: 1200 × 600mm, 100 and 140mm, with a flexible edge for a tight friction fit between timber studs and rafters.

Read Understanding acoustic insulation, work out quantities with the insulation calculator, or compare Isover, URSA and ODE acoustic rolls. For rolls and Rockwool slabs together, see acoustic insulation.

Why buy from Insulation Warehouse Direct

Every product page shows the ex-VAT price, pack size and coverage, so you can price a job and order online in minutes. For bulk or project quantities, call 03330 908479 or email sales@insulationwarehousedirect.co.uk for a quote.

Delivery

Prices are ex-VAT trade prices. Delivery is free to England on insulation orders over £400 ex VAT, which is also our minimum order. We deliver across London, the Midlands and Yorkshire, as well as the rest of England. Orders arrive on a Moffett lorry with forklift offload, so someone needs to be on site, and we’ll call to arrange a delivery day that suits you. Questions or a large order? Call 03330 908479.

Related guides

5 products

Rockwool slabs: buying guide

Rockwool stone wool slabs are dense, rigid enough to friction-fit, and non-combustible (Euroclass A1). We stock two: RWA45 acoustic slab and Rockwool Flexi.

RWA45 or Flexi?

  • RWA45 (1200 × 600mm, 50, 75 and 100mm, 45kg/m³, λ 0.035 W/mK) is the denser slab for partitions, separating floors, ceilings and walls where sound matters.
  • Flexi (1200 × 600mm, 100 and 140mm; λ 0.038 W/mK for 50–120mm and 0.035 W/mK for 140mm and above, per Rockwool’s datasheet) has a flexible edge that springs into place between timber studs, joists and rafters, so it’s mainly used for thermal insulation in timber frames, floors and roofs.

Getting good sound insulation

The slab is only one part of an acoustic wall or floor. Stud width, board type (for example soundboard plasterboard), resilient bar and sealing gaps with acoustic sealant all make a difference. Our guide to acoustic insulation explains the basics.

How many packs?

Each pack shows its coverage in the product name (for example 2.88m² for 100mm RWA45). The insulation calculator works out packs with a waste allowance, and the drywall partition calculator prices a complete stud wall.

Delivery and minimum order: prices are shown ex VAT. We deliver to England. There’s a £400 ex VAT minimum order, and delivery is free on every order. Need a price for a large or mixed load? Call 03330 908479.

Frequently asked questions

Is RWA45 good for soundproofing a stud wall?

RWA45 is a dense acoustic slab designed for partitions and separating floors. The result depends on the whole wall build-up, including board type, stud width and sealing, so follow a tested system where performance is specified.

Can Rockwool Flexi be used in a loft or roof?

Flexi is designed to friction-fit between timber studs, joists and rafters, so it’s commonly used in pitched roofs and timber floors. Check ventilation and vapour control requirements for your roof.

Is Rockwool fire resistant?

Stone wool is non-combustible (Euroclass A1). Fire resistance of a wall or floor depends on the complete tested system.

How many slabs are in a pack?

Pack coverage is shown in the product name, for example 2.88m², 4.32m² or 6.48m² depending on thickness. Divide your area by the pack coverage and add waste, or use our insulation calculator.

Is there a minimum order and how much is delivery?

There’s a £400 ex VAT minimum order on insulation and building materials. Delivery to England is free on every order.

The Rockwool RWA45 Acoustic Insulation Slab is a multi-purpose solution built for thermal, acoustic, and fire insulation. Lightweight and easy to cut into shape, it is suitable for walls, floors, ceilings, and roofs. With dimensions of 1200mm x 600mm and a variety of thickness options, it can be tailored to fit your exact project specifications.

Features include:

  • Excellent thermal and acoustic performance
  • Non-combustible stone wool core for fire-resistant protection
  • Moisture-repellent properties to maintain structural integrity

Designed for ultimate flexibility and adaptability, the Rockwool Flexi Slab is perfect for applications in residential buildings where precision matters. Its unique dual-density edge ensures a snug fit, working exceptionally well in timber or steel frame constructions and cavity walls.

The versatile Rockwool Duo Slab delivers outstanding acoustic insulation alongside superior thermal resistance. Ideal for external walls, it helps reduce heat loss while mitigating sound transmission across various building applications.

For roof applications, Rollbatt Insulation Rolls provide enhanced thermal coverage and soundproofing. Lightweight and robust, it’s an excellent choice for loft spaces where energy-saving insulation can make the most significant difference.

Minimise sound transmission between rooms or through walls, creating quieter, more comfortable living spaces. Whether for home offices or multi-residential complexes, reducing noise pollution is crucial to maintaining productivity and peace.

The non-combustible nature of stone wool insulation provides peace of mind in the face of fire risks. Suitable for walls, roofs, and floors, Rockwool slabs help protect structures by preventing the spread of flames.

By retaining heat effectively, Rockwool insulation reduces the need for excessive heating or cooling systems. The result? Lower energy bills and a smaller carbon footprint.

Stone wool materials are durable and resistant to settling, sagging, and moisture intrusion. A one-time installation delivers performance that lasts decades, with minimal need for maintenance.

Whether closing cavities, insulating steel frames, or addressing soundproofing challenges, Rockwool products are designed to meet diverse construction needs with ease.