Rockwool RW3 50mm (8 Slabs per Pack)
ROCKWOOL RW3 50mm is a semi-rigid stone wool insulation slab designed for acoustic absorption, thermal insulation and non-combustible fire performance in suitable building constructions.
With a nominal density of 60kg/m³ and thermal conductivity of 0.034 W/mK, RW3 is suitable for specified internal walls, partitions, separating walls, intermediate floors, ceilings and roofs.
Each standard unfaced pack contains 8 slabs measuring 1200 x 600 x 50mm, providing 5.76m² of insulation coverage.
Where Can ROCKWOOL RW3 50mm Be Used?
Walls & Partitions
Suitable for specified internal partitions, timber and metal stud walls, and separating wall systems where acoustic and thermal insulation are required.
Intermediate Floors & Ceilings
Helps absorb sound and limit heat transfer within suitable floor and ceiling constructions.
Acoustic Insulation
The stone wool fibre structure absorbs sound energy, helping contribute to acoustic performance when incorporated into a correctly designed construction.
Thermal & Fire Performance
Offers thermal conductivity of 0.034 W/mK and Euroclass A1 non-combustible reaction-to-fire classification for standard unfaced slabs.
The acoustic performance of a complete wall, floor or ceiling depends on its construction, lining materials and installation details.
Product & Pack Information
| Product | ROCKWOOL RW3 Stone Wool Slab |
|---|---|
| Thickness | 50mm |
| Slab Size | 1200 x 600mm (unfaced) |
| Pack Quantity | 8 slabs |
| Pack Coverage | 5.76m² |
| Nominal Density | 60kg/m³ |
| Thermal Conductivity | 0.034 W/mK |
| Thermal Resistance | Approx. 1.47m²K/W (calculated) |
| Reaction to Fire | Euroclass A1 |
| Material | Stone Wool |
| Product Standard | EN 13162:2012+A1:2015 |
Based on ROCKWOOL's March 2026 RW Slabs technical datasheet. Thermal resistance is calculated from nominal thickness and declared conductivity. Verify project-specific requirements against current manufacturer documents.
One Pack Covers 5.76m²
Each standard unfaced RW3 50mm slab measures 1200 x 600mm, giving 0.72m² per slab. With eight slabs per pack, divide the required insulation area by 5.76 and round up to a full pack.
Example: 10m² ÷ 5.76 = 1.74, so you would need 2 packs, before allowing for cutting waste.
Standard unfaced slab calculation. Faced products may have different dimensions and pack coverage.
Other ROCKWOOL RW Insulation Slabs
Need a different thickness or density? Compare the other ROCKWOOL RW slab products available from Insulation & More.
Looking for Dedicated Duct Insulation?
ROCKWOOL RW3 is a multi-purpose stone wool insulation slab for general building applications. For ventilation and HVAC ductwork, purpose-designed ROCKWOOL Duct Slab or Duct Wrap may be more suitable.
Confirm the required insulation thickness, facing, fixing method and thermal performance before selecting materials.
ROCKWOOL Manufacturer Documentation
Access the manufacturer's current technical information, installation guidance, test reports and product certification.
ROCKWOOL RW3 50mm FAQs
RW3 is a stone wool insulation slab used for acoustic, thermal and fire-performance insulation within suitable walls, partitions, floors, ceilings and roof constructions.
ROCKWOOL RW3 has a nominal density of 60kg/m³, as stated in the manufacturer's technical datasheet.
This product is supplied in packs of eight slabs, each measuring 1200 x 600 x 50mm for the standard unfaced version. Total pack coverage is 5.76m².
Yes. RW3 stone wool provides acoustic absorption and can contribute to sound insulation within suitable wall, floor and ceiling constructions. Final sound reduction depends on the complete system.
RW3 has a nominal density of 60kg/m³, compared with 100kg/m³ for RW5. Both provide acoustic, thermal and non-combustible insulation performance. The correct grade depends on the project specification.
Yes. Standard unfaced ROCKWOOL RW3 has a Euroclass A1 reaction-to-fire classification. The fire-resistance performance of a wall or floor depends on its complete construction.
Choose the thickness required by your construction design. The 100mm slab provides greater thermal resistance than the 50mm slab. Acoustic performance depends on the complete system, not thickness alone.
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.