100mm Acoustic Insulation
Not every insulation layer changes how a room feels, but 100mm acoustic insulation often does. It adds depth where sound needs to be controlled, without taking over the structure. Used correctly, it reduces noise transfer and improves how spaces work day to day.Here you will find a clear explanation of what it is and how to use it properly.
What is 100mm acoustic insulation?
100mm acoustic insulation is a full-depth fibrous layer, typically mineral wool (glass or stone wool), fitted within a wall, floor, or roof cavity. Its performance comes from three linked effects:
- Absorption – fibres convert part of the sound energy into heat
- Airflow resistance – helps reduce sound transmission through the cavity
- Damping – reduces cavity resonance and vibration that can amplify sound
At this thickness, it controls the acoustic behaviour of the cavity as a system.
Products are supplied as:
- 100mm acoustic insulation slab – semi-rigid slabs for friction-fit installation
- 100mm acoustic insulation roll – flexible layers for fast coverage
Common product examples include Rockwool acoustic insulation 100mm and Knauf 100mm acoustic insulation, available as slabs or rolls. Both are designed to help meet typical UK partition and floor specifications.
Their typical thermal conductivity range (0.032 W/mK – 0.044 W/mK) contributes to thermal insulation performance. Acoustic behaviour is driven more by density, thickness, and fit than by conductivity alone.
What is 100mm acoustic insulation used for?
This thickness is used where the goal is to reduce sound transmission through the structure. The focus is on limiting transmission paths.
Internal walls (stud partitions)
100mm insulation reduces airborne sound between rooms. The insulation fully fills the cavity, helping to suppress internal resonance. It also helps improve overall partition sound insulation, reducing sound transmission through plasterboard linings.
Intermediate floors (timber joists)
It is placed between joists, where it reduces airborne sound transfer between storeys. It also helps to dampen cavity resonance. The insulation works alongside floor mass and ceiling linings to reduce airborne sound transfer and damp cavity resonance.
Roofs and loft conversions
It reduces external airborne noise ingress, such as rain or traffic, when used between rafters or ceiling joists while also contributing to thermal performance.
Rainscreen and external wall systems
Denser slabs, including dual-density products, are used behind cladding. These help to manage airborne sound transmission while meeting fire and moisture design requirements.
Thinner insulation mainly reduces internal reflections and restricts airflow paths. 100mm insulation adds measurable resistance across the full cavity depth, improving overall sound reduction when combined with lining mass.
Types of 100mm thick acoustic insulation
At 100mm, products vary more by density and application than by thickness.
Insulation slab (semi-rigid slabs)
- Designed to friction-fit between studs or joists
- Maintain their shape over time if correctly fitted
- Provide consistent density across the cavity
A typical example is 100mm Rockwool Flexi slab acoustic insulation, which includes flexible edges to help reduce gaps during installation.
Insulation roll (flexible insulation)
- Supplied in long lengths for quicker installation
- Better suited to horizontal applications such as floors and ceilings
Options include:
- Standard acoustic insulation roll 100mm formats
- 100mm URSA acoustic insulation roll
- Glass wool rolls from major UK manufacturers
Thermal conductivity by product type
- 0.032 W/mK – Isover CWS 32
- 0.034 W/mK – Rockwool RW3, Rockwool RW4, Rockwool RW5
- 0.035 W/mK – Rockwool RWA45, URSA acoustic partition rolls, Knauf Rocksilk RS45, Rainscreen Duo Slab
- 0.036 W/mK – Isover CWS 36
- 0.037 W/mK – ODE Acoustic Roll
- 0.038 W/mK – Rockwool Flexi Slab Acoustic Insulation
- 0.040 W/mK – Knauf Acoustic Insulation Roll
- 0.044 W/mK – Superglass Acoustic Roll
Differences in acoustic performance are influenced more by density (kg/m³) and installation quality than by small changes in conductivity.
FAQ
Where to find bulk 100mm acoustic insulation for commercial projects?
You can buy 100mm acoustic insulation from Insulation Wholesale. We supply acoustic insulation in bulk, covering slabs and rolls from multiple manufacturers. This allows you to match the product to the specification.
Our team can prepare a fast quote from drawings or quantities, helping you compare options quickly. We offer trade discounts, pallet deals, competitive pricing across UK stock lines, and fast nationwide delivery to your site.
What materials are commonly used for 100mm sound insulation?
The two main materials are:
Stone wool (mineral wool)
- Higher density
- Provides effective acoustic absorption and fire resistance
- Common in slabs for partitions and internal walls
Glass wool
- Lower density, and easy to handle
- Supplied mainly in rolls
- Specified on floors, ceilings, and large coverage areas
Both materials have a fibre structure that slows airflow and absorbs sound. Base your product choice on application, required density, and handling preference.
How to install 100mm sound insulation in a timber frame partition?
- Measure stud spacing (typically 400mm or 600mm centres).
- Cut insulation slightly oversized for a friction fit.
- Install to full depth without compressing the material. Compression lowers performance.
- Ensure edges are tightly fitted to studs to prevent air gaps.
- Complete with plasterboard linings on both sides.
Performance depends on continuity; gaps, compression, and misalignment reduce effectiveness.
What is the best 100mm acoustic insulation for internal walls?
For stud partitions, semi-rigid slabs are generally preferred because they hold position and maintain density.
- RW3/RW4 – widely specified for general partitions
- RWA45 – suitable where a slightly lighter product is acceptable
- Flexible-edge slabs – useful where stud spacing varies
Rolls can be used, though achieving a tight vertical fit is more difficult.
Showing all 14 results
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100mm Isover Acoustic Partition Insulation Roll – Glass Mineral Wool 11m2
100mm Isover Acoustic Partition Insulation Roll is a glass mineral wooldesigned to reduce sound transmission between walls and floors, creating quieter and more comfortable spaces.
£47.62£57.14 Ex VATInc VAT£4.33£5.20 Per m2 Add to cart -
100mm Isover CWS 32 Cavity Wall Slab 3.28m2 Pack
100mm Isover CWS 32 Cavity Wall Slab offers excellent thermal insulation for cavity walls, effectively reducing heat loss and boosting energy efficiency. Lightweight and easy to install, it delivers reliable, long-lasting performance.
£37.84£45.41 Ex VATInc VAT£11.54£13.85 Per m2 Add to cart -
100mm Isover CWS 36 Cavity Wall Slab 6.55m2 Pack
100mm Isover CWS 36 Cavity Wall Slab offers excellent thermal insulation for cavity walls, effectively reducing heat loss and boosting energy efficiency. Lightweight and easy to install, it delivers reliable, long-lasting performance.
£35.31£42.37 Ex VATInc VAT£5.39£6.47 Per m2 Add to cart -
100mm Knauf Acoustic Insulation Roll – Glass Mineral Wool 12.36m2
100mm Acoustic Insulation Roll from Knauf is a Glass Mineral Wool roll, designed for use in internal wall and floor applications, to offer sound absorption and noise reduction properties.
£52.98£63.58 Ex VATInc VAT£4.29£5.15 Per m2 Add to cart -
100mm ODE Acoustic Roll Insulation 7.8m2 Roll
100mm ODE Insulation Acoustic Roll is designed to reduce sound transmission, making it an ideal solution for creating quieter indoor environments. Its flexible and simple-to-install design effectively absorbs sound, making it perfect for both residential and commercial spaces.
£24.41£29.29 Ex VATInc VAT£3.13£3.76 Per m2 Add to cart -
100mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 4.32m2 Pack
100mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
£40.41£48.49 Ex VATInc VAT£9.35£11.22 Per m2 Add to cart -
100mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 2.88m2 Pack
100mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.
£35.16£42.19 Ex VATInc VAT£12.21£14.65 Per m2 Add to cart -
100mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 2.88m2 Pack
100mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.
£21.39£25.67 Ex VATInc VAT£7.43£8.92 Per m2 Add to cart -
100mm URSA Acoustic Partition Roll Insulation 7.20m2 Roll
100mm URSA Acoustic Roll is a lightweight, non-combustible, unfaced glass mineral wool product for use as acoustic insulation in timber or metal framed internal partition walls, timber or metal framed separating walls and timber separating floors.
£29.98£35.98 Ex VATInc VAT£4.16£4.99 Per m2 Add to cart -
100mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 3.6m2 Pack
100mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.
POA Get a quote -
100mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 46.08m2 Pallet
100mm Rainscreen Duo Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.
POA Get a quote -
100mm Rockwool RW4 Acoustic Insulation Slab 1200mm x 600mm 34.56 m2 Pallet
100mm Rockwool RW4 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.
POA Get a quote -
100mm Rockwool RW5 Acoustic Insulation Slab 1200mm x 600mm 34.56m2 Pallet
100mm Rockwool RW5 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.
POA Get a quote -
100mm Superglass Acoustic Roll 12 Insulation 12.12m2 Roll
Acoustic Roll 12 is a lightweight, non-combustible glass mineral wool insulation roll. The product is designed to provide thermal and acoustic insulation for several applications, including internal floors and partitions. Manufactured at a minimum density of 12kg/m3.
POA Get a quote
