Rockwool RW3 100mm (4 Slabs per Pack)
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Rockwool RW3 100mm (4 Slabs per Pack)
Description
Description
Rockwool RW3 100mm (4 Slabs per Pack)
ROCKWOOL RW3 100mm is a semi-rigid stone wool insulation slab designed to provide acoustic absorption, thermal insulation and non-combustible fire performance in suitable building constructions.
With a nominal density of 60kg/m³ and a thermal conductivity of 0.034 W/mK, RW3 is suitable for specified walls, partitions, intermediate floors, ceilings and roofs.
Each standard unfaced pack contains 4 slabs measuring 1200 x 600 x 100mm, providing 2.88m² of insulation coverage.
Where Can ROCKWOOL RW3 100mm Be Used?
Walls & Partitions
Suitable for specified timber and metal stud partitions, internal walls and separating wall constructions where acoustic and thermal insulation performance is required.
Floors & Ceilings
Used within suitable intermediate floor and ceiling systems to absorb sound and help limit heat transfer between spaces.
Acoustic Insulation
The stone wool fibre structure helps absorb sound energy. ROCKWOOL's published acoustic absorption data reports an αw value of 1.00 for 100mm RW3.
Thermal & Fire Performance
Provides thermal conductivity of 0.034 W/mK and Euroclass A1 non-combustible reaction-to-fire classification for the unfaced slab.
Acoustic performance of a complete wall, floor or ceiling depends on the full construction. An absorption rating is not the same as a sound-reduction rating.
Product & Pack Information
| Product | ROCKWOOL RW3 Stone Wool Slab |
|---|---|
| Thickness | 100mm |
| Slab Size | 1200 x 600mm (unfaced) |
| Pack Quantity | 4 slabs |
| Pack Coverage | 2.88m² |
| Nominal Density | 60kg/m³ |
| Thermal Conductivity | 0.034 W/mK |
| Thermal Resistance | Approx. 2.94m²K/W (calculated) |
| Sound Absorption | αw 1.00 (100mm RW3 test data) |
| Reaction to Fire | Euroclass A1 |
| Material | Stone Wool |
| Product Standard | EN 13162:2012+A1:2015 |
Based on ROCKWOOL's official RW Slabs technical datasheet (March 2026). Check the manufacturer's current documentation and project requirements before installation.
One Pack Covers 2.88m²
Each standard unfaced RW3 slab measures 1200 x 600mm, providing 0.72m². With four slabs per pack, divide your total insulation area by 2.88 and round up to the nearest full pack.
Example: 10m² ÷ 2.88 = 3.47, so you would need 4 packs before allowing for cutting waste.
This calculation assumes standard unfaced 1200 x 600mm slabs. Faced ROCKWOOL slabs may have different dimensions.
Other ROCKWOOL RW Insulation Slabs
Need a different thickness or density? Explore the other available ROCKWOOL RW insulation slabs to suit your project specification.
Looking for Dedicated Duct Insulation?
ROCKWOOL RW3 is a multi-purpose stone wool insulation slab for building applications. For air-conditioning and ventilation ductwork, purpose-designed ROCKWOOL Duct Slab or Duct Wrap may be more suitable.
Check your project's requirements for thermal performance, surface facing, insulation thickness and fixing methods before selecting a product.
ROCKWOOL Manufacturer Documentation
Review the manufacturer's technical information, installation instructions and supporting certification when specifying ROCKWOOL RW3.
ROCKWOOL RW3 100mm FAQs
What is ROCKWOOL RW3 100mm used for?
RW3 is used for thermal, acoustic and fire-performance insulation within suitable partition walls, separating walls, intermediate floors, ceilings and roof constructions.
What is the density of ROCKWOOL RW3?
ROCKWOOL RW3 has a nominal density of 60kg/m³, as specified in the manufacturer's RW Slabs datasheet.
How many slabs are in an RW3 100mm pack?
This product is sold as four slabs per pack. Standard unfaced slabs measure 1200 x 600 x 100mm, covering a total of 2.88m².
Is ROCKWOOL RW3 100mm suitable for sound insulation?
Yes. RW3 provides acoustic absorption and can contribute to sound insulation performance within correctly designed building constructions. ROCKWOOL reports an αw sound absorption coefficient of 1.00 for 100mm RW3.
What is the difference between RW3 and RW5?
RW3 has a nominal density of 60kg/m³, while RW5 has a nominal density of 100kg/m³. Both offer thermal, acoustic and non-combustible insulation properties. Select the grade specified for your construction.
Is ROCKWOOL RW3 non-combustible?
Yes. Standard unfaced RW3 has a Euroclass A1 reaction-to-fire classification. Fire-resistance ratings of complete wall, floor or ceiling constructions must be verified separately.
Can I use RW3 100mm in a stud wall?
RW3 can be used in suitable timber and metal stud wall systems, provided the thickness, installation method and overall construction comply with the relevant specification.
Need Insulation for a Trade or Commercial Project?
We supply ROCKWOOL and specialist insulation materials for builders, M&E contractors, HVAC installers and commercial projects. Contact our team for product enquiries and project quantities.
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