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Rockwool Building Slabs

Standard Rockwool Product, generally readily available in most thickness’s at the lower densities such as 45kg/m² and 60kg/m². As the slab densities increase, and product popularity declines, short lead times will apply.

Product Functions

The Rockwool RW Slab Range is used for thermal, acoustic and fire insulation in general building applications, certified to EN 13162.
These slabs are particularly suitable for acoustic infills in partitions and ceilings, providing a high level of control of both airborne and structure-borne sound. They are also suitable for acoustic absorption in the linings of buildings.

Product Description

Rockwool Building Slabs for installation versitility around the house

Rockwool Building Slabs are a range of rigid and semi-rigid, resilient, non-combustible rock mineral wool slabs,available in densities from 33 to 140kg/m . The standard products are supplied un-faced, but they can also be manufactured with a factory applied foil or tissue facing, they are also available in a water repellent grade.

The product range consists of high quality resin bonded slabs in a variety of thicknesses and densities.

Mineral slabs of a density of 45 kg/m³ have now become the de-facto standard for normal domestic insulation purposes. Densities above this level are particularly good for use in sound studios and commercial and industrial areas where, for example, machine noise is prevalent.

Availability: These products are popular, and are generally readily available. Heavier densities may have lead-time requirements. Please review the availability indicators.

Additional Options: RW slabs are also available with number of facing options, which are:

  • Non-woven mineral black tissue (75gsm)
  • Non-woven mineral white tissue (100gsm)
  • Aluminium foil

These options need to be priced on application, and need to achieve realistic economies of scale. Therefore, minimum order sizes will apply

Product Benefits

Excellent thermal, acoustic and fire insulation
Suitable for a wide range of general building applications
Euroclass A1 to BS EN 13501-1
Easy to handle and install
No maintenance
Black or white tissue and aluminium foil facings available
Cost effective

Product Performance


Rockwool continues to work throughout the lifetime of the building. As well as reducing the heat needed to keep buildings warm in winter, stone wool insulation also maintains a cool interior temperature in summer. It’s energy efficient as well as being environmentally friendly all year round


All Rockwool RW slab products, either un-faced or with an aluminium foil or glass fleece on one or both surfaces, achieve an A1 classification in accordance with BS EN 13501-1 and therefore comply with the requirements of non-combustible materials/products, as defined in all UK and Ireland Building Regulations.

Water resistance

Rockwool RW Slabs are highly water repellent and non-hygroscopic

Thermal performance

For general building applications (Lambda 90:90) at temperature 10 degrees C:

Rockwool RWA45 slab = 0.035 W/mK | Rockwool RW3 slab = 0.034 W/mK | Rockwool RW5 slab = 0.034 W/mK

Handling and Storage

Rockwool RW slabs are light and easy to cut to any shape with a sharp knife. They are shrink wrapped in polyethylene and supplied on pallets which are shrouded with a waterproof hood suitable for outside storage.

All standard un-faced slabs are manufactured 1200 x 600mm. All foil faced and tissue faced slabs are manufactured 1000 x 600mm. The standard thickness range of Rockwool RW slabs are shown in the table below. * Denotes thickness also available as ‘standard’ with white or black tissue facing (not foil facing). All foil faced and tissue faced slabs (other than shown above) are non -standard and will be subject to minimum order quantities.

Product availability indicators

Rockwool Mineral Wool Products - Price and Availability Advisory:

Presently there are no availability restrictions.

Excellent = Product Availability Excellent  Good = Product Availability Good  Fair = Product Availability Fair  Poor =  Product Availability Poor  Undetermined = Product Availability Undetermined
Availability relies on stock levels at closest depots and upon transport logistics to effect deliveries

Technical Data


The Rockwool Building Slab Range comprises of the following high quality resin bonded 1200mm x 600mm slabs, branded as follows …
SL 920 / RWA45 (Density = 45kg/m³ - Thickness’s = 30, 40, 50, 60, 75, & 100mm)
SL 930 / RW3 (Density = 60kg/m³ - Thickness’s = 25, 30,40, 50, 60, 75 & 100mm)
SL 950 / RW4 (Density = 80kg/m³ - Thickness’s = 50, 75 &100mm)
SL 960 / RW5 (Density = 100kg/m³ - Thickness’s = 25, 30,40, 50, 60, 75 & 100mm)
SL 980 / RW6 (Density = 140kg/m³ - Thickness’s = 30, 50, 75, & 100mm)

Specialist sizes and thickness’s, which are available for special order.

Note: For reasons best known to the Rockwool Marketing Department, Rockwool have recently inflicted new naming conventions upon the Public.
Firstly, there was a rebranding excersise in which the name Prorox would randomly appear on some but not all products. Then, there was the renaming of building slabs ... for example Rockwool 'RW3' became Rockwool 'SL 930". To avoid confusion we have used both names when referring to these products.


Non-woven mineral black or white tissue and aluminium foil faced 1000 x 600mm slabs , which are also available for special order. Minimum quantity levels will apply.


No CFCs, HFCs or HCFCs are used in the manufacture of Rockwool materials.

Water resistance

Rockwool ProRox Slabs are highly water repellent. Where it is necessary to maintain water repellent properties subsequent to heating at elevated temperatures, the use of WRG slabs is recommended.

Resistance to compression

Stress required to produce 10% compression (kN/m2) = 6.7
Stress required to reach elastic limit ∂e (kN/m2) = 6.1
Displacement at 5 kN/m2 stress = 7.8
Tested in accordance with BS EN 826: 1996

NB Elastic limit occurs between 6 and 12% deformation.


Rockwool stone wool works in two distinct ways to reduce noise, either by impeding the transmission of sound through an element of the structure or by absorption of
sound at the surface.
Noise absorption is expressed as a factor between 0 and 1.0.
The more sound that a surface absorbs, the higher its absorption coefficient.
The structure of the fibres in Rockwool Slabs make them ideal for use as a sound absorber, with characteristically high coefficients over a wide frequency range

Tissue faced slabs

Rockwool can manufacture a wide range of tissue faced, line produced slabs, ranging from 45 kg/m3 to 140 kg/m3.
Black and white tissue faced options available upon request
Tissue faced slab size: 1000mm × 600mm
The tissues are bonded to the face of the slabs with binder which provides a superior acoustic and fire performance to fabricated, adhesive applied, tissue faced products.
Tissue facings available, 70gm black and 100 gm white tissue options are available, and details are available upon request

Properties Details
Dimensions 600mm x 1200mm (1000mm for faced slabs)
Thickness 25mm - 100mm
Thermal Conductivity 0.034 - 0.035 W/mK
Performance and Properties Euroclass A1
Water Repellency Water Repellent
Vapour Resistivity Negligable
Environmental Zero ODP & GWP
Standards BS EN 13162, ISO 14001: 2004

Product Information and Certification

Links to manufacturer's information. Click to download in a separate browser window.

Rockwool Building Slab Datasheet | Rockwool Cavity Wall Slab BBA Certificate | Rockwool meeting Part L Building Regs.


Rockwool Building Slab Range - Certification

Product Certification

Rockwool has been examined by the British Board of Agrément and granted BBA Certificate 94/3079 for use in all exposure zones for buildings up to 12 m in height and for buildings over 12 m and up to 25 m in height in zones where the exposure factor does not exceed 120.

To comply with the requirements of the Agrément Certificate, and to ensure trouble free performance, the masonry walls must be built in accordance with BS 5628:Part 3: 1985 or BS 5390: 1976, as appropriate, and the workmanship on site must comply with BS 8000: Part 3: 1989.

Rockwool Slabs conform to BS EN 13162: 2001: Thermal insulation products for buildings – factory made mineral wool (MW) products specification.

They also satisfy the requirements of BS 5422: Method for specifying thermal insulating materials for pipes, tanks, vessels ductwork and equipment.

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Contact Manufacturer

Rockwool Insulation Limited

Pencoed Bridgend CF35 6NY United Kingdom

Rockwool Customer Service

Telephone: +44 (0) 1656 868400
Web site: Rockwool Home Page

Contact us

Insulation Online Limited

Sales Office only:39 Normandy Road, Worthing, West Sussex, BN14 7DX, UK

Telephone: 0333 8000 828


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