Rockwool Acoustic Mineral Wool RW3 75mm 60kg/m³

Shipped by iKoustic from the UK


£59.94 inc. VAT

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    • Soundproof Mineral wool to be used in soundproof partitions.
    • A crucial component for all soundproofing systems with joists, battens, acoustic cradles or stud-frames.
    • Euroclass A1 fire rating.
    • Dimensions: 1200mm x 600mm x 75mm. (6 Slabs 4.32m2)
    • Weight: 20kg


Rockwool Acoustic Mineral Wool RW3 75mm 60kg/m³

Rockwool Acoustic Mineral Wool (RW3) (60kg per m3) is high-density acoustic mineral wool that is used to treat cavities, between flooring joists, stud-frame walls and battened ceilings.

Acoustic Mineral Wool works by lessening sound energy helping to decrease the remaining noise ‘bouncing’ around inside the cavity and amplifying (like a drum). We recommend using Rockwool RW3 as part of a system or to reduce Flanking transmission.

Acoustic Mineral Wool Coverage Calculator
Single Product Calculator – Mineralwool 75mm
Rockwool RW3 Mineral Wool
Bass Frequency

Bass frequency absorption

Bass frequencies are difficult to treat with soundproofing. Rockwool RW3 has a good absorption coefficient at bass frequencies, making it an essential upgrade to most soundproofing systems.

Double room

Multi-use application

Whether you are treating your wall, floor or ceiling Rockwool RW3 is ideal to fill joists, stud frames, battens and acoustic cradles.

Installing Acoustic Mineral Wool

Easy to install

Cut your slabs slightly larger than the application area and simply pressure fit them to hold them in place.

Fire rated 01

A1 fire rated

Rockwool RW3 has a Euroclass A1 fire rating, meaning it is completely non-combustible. This is an excellent safety feature and is often required for building regulations.

Thermal insulation

Thermal insulation

Alongside its enhanced acoustic capability acoustic mineral wool carries the same thermal insulation properties as its standard counterpart. Rockwool RW3 has a thermal conductivity of 34 W/mK.

Other thicknesses we offer:

Mineral wool thickness100mm75mm50mm25mm
Slabs per bale/m24 Slabs (2.88m2)6 Slabs (4.32m2)8 Slabs (5.76m2)16 Slabs (11.52m2)
Woll bales illustration 01 1
  1. Although acoustic insulation used here is not toxic or hazardous, when installing mineral wool does release small dust particles, so do use gloves, goggles and a face mask.
  2. Measure the depth of the cavity first, or if you know the stud depth you are using, make sure that you choose a depth of Acoustic Mineral Wool that allows for a 10mm air gap on either side.
  3. The reason you leave this air gap is to avoid compressing the fibrous properties between the two partitions you are soundproofing, for example, do not use a 100mm depth in a 50mm gap.
  4. Acoustic Mineral Wool is easy to cut with large scissors, or we found a bread knife to be a great tool here.
  5. Cut the slab a little larger than the stud or joist gap to friction hold, or use a form of wiring to hold it in place.

Soundproof plasterboard works best as part of a system like our MuteClip systems, or when combined with other materials.

60kg is the density of the product when measured in cubic meters and not the weight of a single slab or bale of acoustic mineral wool – it is a reasonably lightweight sound insulation product that is easy to cut and easy to lay, use gloves and eye protection and keep the area ventilated during and after installation.

The slab mineral wool is much higher density and far better for airborne sound absorption and reduction, especially at base frequencies.

Yes, the 60kg/m2 mineral wool has a thermal conductivity of 0.034 W/mK.

The insulation boards improve the thermal rating but do not absorb sound within a cavity so the mineral wool will improve both thermal and acoustic!

The 75mm thickness is best used as stud wall insulation, between flooring joists or in flooring frameworks to prevent cavities from resonating, leaving them untreated can lead to the remaining sound passing through into these areas and bypassing the soundproofing. You will also want to avoid using a thicker size than the air gap provided and aim to have at least a 10mm air gap – using a 100mm thickness in a 50mm cavity, for example, will lead to compression of the acoustic mineral wool and a direct path of sound to travel through – degrading the performance of the sound proofing system.

You will want to install acoustic mineral wool in timber and metal frameworks, in our suspended ceiling or wall systems such as in our MuteClip System and flooring cavities between joists or with our MuteCradle options it can be used to treat all these cavities to reduce sound from bouncing around inside them and resonating. But, it is essential to note that this is a lightweight, fibrous material and this means that sound will pass through it – so it is not effective in reducing airborne nor impact noise issues as a standalone solution.

As a fibrous material, it can lead to slight irritation of the skin, those with sensitive skin may find a slight redness appear while handling it – the use of gloves and protective eyewear is recommended.

Find out more information about Rockwool Acoustic Mineral Wool by downloading the guide below.

Product Data Sheet

If you are looking to specify this product for a build, please refer to our downloads tab for technical product or systems information.

Technical Support
Should you require further technical assistance in specifying our products, please contact us and ask for our Technical Rep, Gabriel Whittle.

BIM Objects
iKoustic also supply a selection of BIM objects via our NBS profile, which can be found here. 

Important Information

Our products contain a high level of mass. If there are any structural concerns you will want to consult a Structural Engineer to discuss your requirements.

*Our Typical Performance Results and Noise Reduction Guidance are provided to indicate the results that have been achieved in previous tests but are not guaranteed to a specific site as multiple factors can affect this, you can view their variants on our ‘Featured Systems’ tab.

Delivery information.

If you place an order online it’s likely we will call to discuss delivery to make sure it runs as smoothly as possible. Deliveries can arrive on a large vehicle. If there are access issues or HGV restrictions, please do let us know in advance as our website options are given in good faith of no restrictions. All of our deliveries must be signed for so you will need to ensure someone is on the premises on the day of delivery.

Delivery Times