Knauf Rocksilk® RS45 is a high-performance rock mineral wool slab designed for projects that need reliable acoustic absorption, thermal insulation, and fire protection — all from one product. It’s non-combustible and achieves Euroclass A1 reaction to fire classification, with a melting temperature of over 1000°C for longer periods of fire resistance than many mainstream insulants.
RS45 is also manufactured using Knauf’s plant-based binder, ECOSE® Technology, and its mineral wool structure delivers excellent levels of sound absorption and sound reduction.
Key benefits
- Multi-application slab: one product for multiple build-ups
- Excellent acoustic performance: strong sound absorption and reduction
- Non-combustible: Euroclass A1 reaction to fire classification
- High temperature resistance: melting point over 1000°C
- Made with ECOSE® Technology (plant-based binder)
Typical applications
- Ground floors
- Internal floors
- Separating floors
- Pitched roofs (at rafter level)
- Internal walls / partitions
- Light steel frame walls
- Timber frame walls
- Fabrication / general build-ups
Sizes & options
- Slab size: 600mm x 1200mm
- Thickness options: 25mm, 50mm, 100mm
Pack coverage
- 25mm: 14.4m² per pack (20 slabs)
- 50mm: 7.2m² per pack (10 slabs)
- 100mm: 3.6m² per pack (5 slabs)
To quickly find out the shipping cost for your order simply add the required items to your cart. Place your cursor over the cart icon at the top of the page. Click on "Calculate Cart Shipping". Select your country and region and enter your postcode. The shipping rate will be displayed. If your country is not listed please contact us for a shipping quote.
UK Shipping Charges For Most Products
Orders with a value of £0.00 to £54.99 have a £7.00 carriage charge with tracked next working day delivery.
Orders with a value of 55.00 to £99.99 have a £12.00 carriage charge with tracked next working day delivery.
Orders with a value of £100.00 or more qualify for free next day shipping.
Excluded Items
For carts which contain Plasterboard, Soundproofing Mat, SilentBoard, QuietPanel, Silent Floor Ultra, M20 and R10 the following charges apply
£8.00 carriage for the first item and £4.00 carriage for every item added up to a maximum charge of £75.00.
Some soundproofing items have a minimum order due to shipping constraints.
Bulk Products have a £75.00 pallet charge per item.
Returns
Our policy lasts 30 days. If 30 days have gone by since your purchase, unfortunately we can’t offer you a refund or exchange. To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Non-returnable items:- Made to order items such as our Office Acoustic Panels and High End Audio Acoustic Panels, Gift cards.
To complete your return, we require a receipt or proof of purchase. Please contact us for your return authorisation number. Once your return is received and inspected, we will send you an email to notify you that we have received your returned item.
Exchanges
We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at info@advancedacoustics-uk.com and send your item to: Advanced Acoustics LTD, Unit B, Maunside, Green Line Industrial Estate, Mansfield, NG18 5GU, United Kingdom.
