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Split your purchase of £23.99 into 4 with no sign-up fees or late fees. Your purchase will be split into 4 payments, payable every 2 weeks
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Key Features
{{volume_off}} Excellent acoustic and thermal performance
Stone wool insulation slab, measuring 100mm in thickness, designed for use in internal partitions, floors, and roof applications.
Manufactured from high-density stone wool, the slab combines excellent acoustic absorption with reliable thermal insulation and inherent fire resistance.
Its rigid composition allows a close friction fit between studs or joists, preventing gaps that could compromise performance.
Non-combustible and classified as Euroclass A1, the slab contributes to improved fire safety within the building fabric. Its fibre structure also provides effective sound reduction, limiting noise transfer between rooms and floors.
At 100mm thick, this slab is the most widely specified option in the RWA45 range.
It is particularly suited to stud walls and intermediate floors, where its depth provides robust sound insulation alongside strong thermal and fire performance.
Euroclass A1 fire classification: Non-combustible in accordance with BS EN 13501-1.
Stone wool mineral slab: Naturally resistant to rot, fungal decay, and insect attack.
Square-cut edges: Butt together cleanly for continuous insulation layers.
Porous fibre structure: Absorbs sound energy, reducing noise transfer through walls and floors.
Semi-rigid slab: Simple to shape with a knife and friction-fit between studs or joists.
Thermal conductivity 0.035 W/m·K: Helps maintain building energy efficiency.
Sustainable manufacture: Made from natural volcanic rock, recyclable, zero ODP/GWP.
100mm thickness: Delivers maximum thermal and acoustic performance in the RWA45 range.
Applications
Stud partitions with maximum acoustic demand: Provides the highest level of airborne sound reduction.
Intermediate floors with deep joists: Delivers top performance for separating floors.
Ceilings beneath noisy spaces: Best solution for reducing sound transfer.
Drylined partitions and linings: Maximises fire, thermal, and acoustic ratings.
Home studio soundproofing: High-density 100mm slabs provide the necessary acoustic mass to significantly reduce sound transmission and internal reflections in recording environments.
HMO party wall upgrades: Non-combustible mineral wool construction ensures compliance with Building Regulations Part E for sound insulation in multi-occupancy dwellings.
Home cinema rooms: Maximum thickness 100mm profile delivers superior sound absorption within wall and ceiling cavities to prevent audio bleed into adjacent residential spaces.
Installation Guidance
Precision cutting: Use a sharp insulation saw or broad-bladed knife to cut slabs slightly oversized to ensure a compressed friction fit.
Seamless abutment: Butt all joints tightly together with no visible gaps to maintain the continuity of the fire and acoustic barrier.
Mechanical support: Secure with appropriate netting or insulation hangers when installing in overhead applications to prevent gravity-induced movement.
Environmental protection: Store slabs undercover and off the ground to ensure the material remains dry and free from contaminants prior to installation.
Personal protection: Wear loose-fitting clothing, gloves, and safety goggles to minimise skin and eye contact with mineral fibres.
Soundproofing Guidance
Mass Enhancement: Combine slabs with high-density soundproof plasterboard to significantly increase the total mass of the partition.
Decoupling Strategy: Use resilient bars or independent stud frames in conjunction with the slabs to prevent mechanical vibration from traveling through the structure.
Acoustic Sealing: Apply acoustic sealant to the perimeter of the partition and around any penetrations to prevent "flanking" noise from bypassing the insulation.
Cavity Management: Ensure the slab fills at least 75% of the cavity depth to provide optimal sound absorption and prevent internal resonance.
Compliance & Performance
Thermal conductivity: Declared 0.035 W/m·K (EN 13162).
Fire performance: Euroclass A1 non-combustible (BS EN 13501-1).
Certification: CE and Key marked to BS EN 13162:2012 + A1:2015.
Acoustic standards: Supports compliance with Building Regulations Approved Document E (England & Wales), Section 5 (Scotland), and BB93 (schools) for acoustic performance in internal and separating walls/floors.
Sound Absorption Class: Achieves Sound Absorption Class A (aw 1.00). The ultimate acoustic barrier, capable of achieving 52dB+ reduction in dual-layer plasterboard systems.
Marine/offshore certification: Lloyd’s Register approved as non-combustible.
Delivery & Returns Information
Delivery charges vary by product category and order value. Items may ship from different suppliers and arrive separately, so delivery charges can be shown per part of your order at checkout.
Standard (Nationwide) Delivery
Insulation, Plasterboard and Drylining Products
ORDER VALUE
DELIVERY CHARGE
Under
£400
£45
ex. VAT
Over
£400
ex. VAT
FREE
Express Delivery
Express Delivery - Insulation and Plasterboard & Drylining
ORDER VALUE
DELIVERY CHARGE
Under
£400
£90
ex. VAT
Over
£400
ex. VAT
£55
ex. VAT
Express Delivery - Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products
We work with a nationwide network of trusted suppliers. Items in your basket may be supplied by different suppliers and delivered separately. Where this applies, you will see delivery charges shown at checkout for each part of your order. We always aim to group products from the same supplier to keep delivery costs as low as possible.
Delivery areas
Delivery charges apply to mainland UK, excluding: AB, CA, CF, DD, DG, EH, EX, FK, KA, KW, KY, IV, LA, LD, LL, ML, NP, PA, PH, PL, SA, SY, TR, TQ and TD.
If your address is in one of these areas, we will contact you before processing your order to confirm any additional costs. We do not currently offer delivery outside the UK mainland.
What to expect on delivery day
Deliveries are typically kerbside.
Please ensure someone is on-site to accept delivery. For heavier items, help with offloading may be required.
Many building materials arrive on large vehicles. If access is restricted, a specialist vehicle such as a HIAB may be required and could incur an additional charge.
Why delivery can cost more than typical parcel delivery
Building materials often travel on larger vehicles and usually carry fewer drops per run than parcel networks. That is why delivery charges can be higher than standard e-commerce shipping.
Returns
Returns depend on what you have bought and whether there is anything wrong with it. For full details on eligibility, timeframes, and exclusions, please see our full policy.
Fantastic product. When it came to adding these in between the studwork, they were simple to fit into place and then to cut I used a bread knife, as I didn't have a drywall knife - the slabs are like you are cutting bread! The RWA45 slabs have helped reduce noise between rooms since I've installed and I would recommend buying them.
Lenny Silverman on
Easy to use
Mo H on
Great insulation as part of a soundproofing solution
Graham Needs on
Arrived on time, thank you
Jill P on
received as expected, thanks
Grace Lint on
We used this in our extension and it's really helped with soundproofing
Ayla Kim on
Arrived on time and did the job
Grant S on
Great product
Ian K on
Really helped to reduce noise between floors
Chris Eldersbury on
Perfect for my new home gym!
Lily L on
Easy to install, just needed a sharp knife to cut the slabs to size for my wall
Alexi H on
Great product, I bought this for the acoustic performance and it was the ideal solution to soundproof my home gym
John Barrett on
Ordered and received to my delivery postcode in 2 days
Pete D on
Completely changed the noise from the hallow stairs between bedrooms. Would buy again.
Martin Chivers on
Great acoustic insulation slabs. Really reduced the sound from upstairs after my daughter moved back in. Next time I need any acoustic and thermal insulation, I'll be sure to come back to this site.
It depends on the area you are working with, but 1he 100mm pack covers 2.88m2. You can also use the calculator on our product page to calculate the number of packs needed.
Is Rockwool RWA45 fireproof?
It is classified as Euroclass A1 non-combustible, which is the highest fire safety rating available for building materials.
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