Knauf 50mm OmniFit Thermal & Sound Glass Mineral Wool Insulation Slab 1200x400mm Pack of 12 (5.76m²)
Knauf 50mm OmniFit Thermal & Sound Slab is a versatile glass mineral wool insulation designed to provide both thermal and acoustic performance across a wide range of wall, floor and pitched roof applications. It is suitable for timber and metal stud partitions, timber frame walls, timber floors and pitched roofs insulated between rafters.
Each pack contains 12 slabs measuring 1200x400x50mm and provides approximately 5.76m² of coverage. The 50mm slab has a declared thermal conductivity of 0.035 W/mK, thermal resistance of 1.40m²K/W and Euroclass A1 reaction-to-fire classification, meaning it is non-combustible.
OmniFit Thermal & Sound Slab also achieves the best possible Sound Absorption Class A and is Quiet Mark certified, making it particularly useful where improved acoustic comfort is required alongside thermal insulation.
Key Features & Benefits of Knauf 50mm OmniFit Thermal & Sound Glass Mineral Wool Insulation Slab:
- Manufacturer: Knauf Insulation
- Range: OmniFit® Thermal and Sound Slab
- Material: Glass Mineral Wool
- Thickness: 50mm
- Slab size: 1200x400x50mm
- Pack quantity: 12 slabs
- Coverage: 5.76m² per pack
- Thermal conductivity: 0.035 W/mK
- Thermal resistance: 1.40m²K/W
- Reaction to fire: Euroclass A1 - non-combustible
- Sound absorption: Class A
- Weighted sound absorption coefficient: αw 0.90 at 50mm thickness
- Acoustic certification: Quiet Mark certified
- Applications: Internal partitions, timber frame walls, timber floors and pitched roofs at rafter level
- Technology: ECOSE® Technology
- Product code: 883299
- Packs per pallet: 36
- Provides thermal and acoustic performance in one insulation product
- Flexible mineral wool helps achieve a close fit around minor irregularities
- Odourless, rot proof and non-hygroscopic
- Does not sustain vermin or encourage the growth of fungi, mould or bacteria
Thermal & Acoustic Insulation in One Slab
Knauf OmniFit Thermal & Sound Slab is designed for applications where both heat loss and unwanted sound need to be considered.
The glass mineral wool structure provides thermal resistance while also absorbing sound energy within wall, floor and roof cavities. This makes OmniFit a practical multi-purpose insulation solution for residential and commercial projects where thermal and acoustic performance are both important.
Where Can Knauf OmniFit Thermal & Sound Slab Be Used?
Knauf specifies OmniFit Thermal & Sound Slab for the thermal and acoustic insulation of a wide variety of constructions, including:
- Timber stud partitions
- Metal stud partitions
- Timber frame walls
- Timber floors
- Internal floors
- Separating floor constructions
- Suspended timber ground floors
- Pitched roofs insulated between rafters
The exact insulation thickness and complete construction build-up should always be selected according to the requirements of the individual project.
Ideal for Internal Walls & Stud Partitions
The 50mm OmniFit slab is particularly useful within internal timber and metal stud partitions where acoustic absorption is required.
The flexible glass mineral wool fits closely within suitable framing, helping reduce gaps within the insulation layer while providing both sound absorption and thermal performance.
Final acoustic performance will depend on the complete partition construction, including the framing, plasterboard specification, fixings and installation quality.
Sound Absorption Class A
Knauf OmniFit Thermal & Sound Slab achieves the best possible Sound Absorption Class A, including at just 50mm thickness.
The 50mm product has a weighted sound absorption coefficient of αw 0.90. Knauf states that Class A sound absorption represents the highest level of acoustic performance, absorbing 90% or more of sound energy across a wide frequency range.
This makes OmniFit an excellent choice for bedrooms, home offices, living spaces and other applications where reducing unwanted noise forms part of the building design.
Quiet Mark Certified
OmniFit Thermal & Sound Slab has been awarded Quiet Mark certification.
Quiet Mark is an independent certification programme associated with the UK Noise Abatement Society charitable foundation and recognises products that make a contribution to protection from unwanted noise.
Independent Acoustic Performance
According to Knauf Insulation, independent testing has shown that OmniFit Thermal & Sound Slab provides the same or superior noise protection as traditional 45kg/m³ low-density rock mineral wool sound slabs.
This allows customers to benefit from the handling characteristics of flexible glass mineral wool while achieving strong acoustic absorption performance.
0.035 W/mK Thermal Conductivity
Knauf OmniFit Thermal & Sound Slab has a declared thermal conductivity of 0.035 W/mK.
At 50mm thickness, the product provides a thermal resistance of 1.40m²K/W.
The overall U-value of a wall, floor or roof depends on the complete construction build-up rather than the insulation slab alone.
Euroclass A1 Non-Combustible Insulation
Knauf OmniFit Thermal & Sound Slab achieves a Euroclass A1 reaction-to-fire classification.
A1 is the best possible Euroclass reaction-to-fire classification and means the glass mineral wool insulation is classified as non-combustible.
Flexible Glass Mineral Wool for a Close Fit
Glass mineral wool can adapt to minor imperfections within the surrounding construction, helping the insulation maintain close contact with framing and reducing unwanted air gaps.
This is important because gaps within an insulation layer can reduce its real-world thermal and acoustic performance.
The flexible slab format also makes OmniFit straightforward to fit between suitable timber or metal framing and around minor irregularities.
Suitable for Timber Floors
OmniFit Thermal & Sound Slab is suitable for a range of timber floor constructions, including internal floors, separating floors and suspended timber ground floors where specified.
Within separating and internal floor constructions, the mineral wool's sound absorption properties can help contribute to the acoustic performance of the complete floor system.
Pitched Roof Insulation at Rafter Level
Knauf also specifies OmniFit Thermal & Sound Slab for pitched roofs insulated at rafter level.
The required insulation thickness, ventilation strategy and complete roof construction should be determined by the project specification and applicable Building Regulations requirements.
Pack of 12 - 5.76m² Coverage
Each pack contains 12 individual slabs measuring 1200x400x50mm.
The complete pack provides approximately 5.76m² of insulation coverage.
When calculating the number of packs required, allow for the actual framed area, openings, cutting and suitable installation wastage.
ECOSE® Technology
OmniFit Thermal & Sound Slab is manufactured using Knauf Insulation's ECOSE® Technology, a plant-based binder containing no added formaldehyde or phenol.
Knauf states that products manufactured using ECOSE® Technology are soft to touch, easy to handle and generate low levels of dust and VOCs.
Recycled Content & Responsible Manufacturing
Knauf states that its glass mineral wool products are manufactured using up to 80% recycled content, including recycled glass from items such as windows, bottles and jars.
Knauf's glass mineral wool products have also received the Declare 'Red List Free' label, while its mineral wool manufacturing plants have achieved BES6001 'Very Good' responsible sourcing certification.
Durable Insulation Performance
Knauf states that OmniFit Thermal & Sound Slab is odourless, rot proof and non-hygroscopic. It does not sustain vermin or encourage the growth of fungi, mould or bacteria.
When correctly installed and protected within the building construction, the product is designed to have a life equivalent to that of the structure in which it is incorporated.
Standards & Certification
OmniFit Thermal & Sound Slab has a product declaration made in conformity with BS EN 13162:2012+A1:2015 for factory-made mineral wool insulation products.
The OmniFit Thermal & Sound Slab product set also holds a CCPI Assessment Mark, providing additional assurance around the clarity, accuracy and accessibility of product information.
Handling & Storage
Store OmniFit Thermal & Sound Slab clean, dry and protected from damage. For longer-term site storage, Knauf recommends keeping the insulation indoors or under suitable weatherproof cover and off the ground.
The product should not be left permanently exposed to the weather or prolonged sunlight. Wet, contaminated or damaged insulation should not be installed.
Knauf OmniFit Technical Datasheet
For complete technical information, performance data, certifications, applications, storage requirements and manufacturer guidance, please refer to the official Knauf Insulation technical datasheet:
View Knauf OmniFit Thermal & Sound Slab Technical Datasheet
Why Choose Knauf 50mm OmniFit Thermal & Sound Slab?
Knauf 50mm OmniFit Thermal & Sound Slab is a versatile insulation solution for projects where both thermal efficiency and acoustic comfort matter. Its combination of 0.035 W/mK thermal conductivity, Sound Absorption Class A, αw 0.90 acoustic performance, Quiet Mark certification and Euroclass A1 non-combustible fire classification gives the product strong technical performance across a wide range of building applications.
With 12 convenient 1200x400x50mm slabs providing 5.76m² coverage per pack, it is particularly well suited to internal partitions, timber frame walls, timber floors and pitched roof constructions where flexible thermal and acoustic glass mineral wool insulation is required.
