Knauf Rocksilk RS45 75mm Building Slab

The 75mm Rocksilk RS45 Knauf Rock Mineral Wool Insulation Slab delivers standard-density (45kg/m3) performance with outstanding fire safety credentials. Classified as Euroclass A1 and non-combustible, this versatile building material suits a wide range of construction needs with excellent thermal and acoustic qualities.

Sized at 1200mm x 600mm, the Knauf RS45 rocksilk insulation slab provides reliable performance for both new builds and refurbishment work.

These slabs are odourless, non-hygroscopic, and naturally rot-proof. They contain no CFCs or HCFCs and resist fungal, mould, and bacterial growth.

With a certified thermal conductivity (λ - lambda value) of 0.035W/mK, the 75mm Knauf RS45 unfaced insulation slab delivers high thermal efficiency.

At 45kg/m3 density, this 75mm RS45 slab works well for internal partitions, timber and metal stud work, and placement between timber rafters and floor joists.

The 75mm Knauf building slabs feature excellent sound absorption, delivering significant sound reduction benefits.

Installation is straightforward—simply cut and shape using a large-bladed knife or saw. 75mm Knauf Rocksilk RS45 insulation slab combines ease of handling with reliable performance.

Product specification

• Brand: Knauf®
• Model: 75mm Rocksilk RS45
• Thickness: 75mm
• Length: 1200mm
• Width: 600mm
• Dimensions: 1,200mm x 600mm x 75mm
• Board Coverage: 0.72m2
• Pack Coverage: 4.32m2
• Pack Quantity: 6
• R-Value: 2.10m2K/W
• Thermal Conductivity: 0.035W/mK
• Density: 45kg/m3
• Colour: Brown
• Material: Rock mineral wool
• Fire Classification: Euroclass A1
• Vapour Resistivity: 5.00MNs/g.m.
• Fire Reaction: Non-combustible
• Building Regulations: Class '0'
• Finish: Unfaced
• Shipping method: Articulated Vehicle ǀ Courier
• Applications: Floor ǀ Wall ǀ Roof ǀ Partitions
• Foil faced: No
• ECOSE Technology: Yes
• ETA Notification: Yes
• Features: Thermal and Acoustic Insulation Performance
• Manufacturer: Knauf Rocksilk®

Made to order Facings

For a factory applied foil or tissue facing please request a quotation using the website form or by calling our agents. We do offer single side or double side foil/tissue facings.

Applications

75mm Rocksilk Building Slabs work brilliantly across numerous building scenarios. Use them between rafters in pitched roof constructions, within intermediate floors, as floor separators, in internal stud partitions, and for light steel frame infill. Original Equipment Manufacturers (OEMs) also rely on these slabs for thermal, acoustic, and fire product fabrication. Thanks to their non-combustible nature, Rocksilk® Building Slabs come in multiple densities from 45kg/m3 up to 140kg/m3, meeting the demands of diverse applications.

Benefits

• One slab type handles many different applications.
• Factory-applied foil or tissue facing options are available, expanding the range of suitable uses.
• Mineral wool construction delivers superior sound absorption and noise reduction compared to many other insulants.
• Made from rock mineral wool with a melting point above 1000°C, providing extended fire resistance compared to standard alternatives.

Info

Browse our full Knauf Insulation range and filter by thickness or coverage using the left-hand menu. Need advice on product suitability for your project or a bulk discount quote? Get in touch by phone on +4402038839057, email sales@insulationbee, or use Live Chat for the best UK Knauf Loft Insulation prices.