Knauf Rocksilk® RS80 Building Slab | 1200mm x 600mm | All Sizes

KnaufSKU: IUK01678

Sale price£41.15 

inc VAT

Pay in 3 prices shown are an example only. Total calculated at checkout.

Delivery within 3 - 5 working days

Free Delivery On Orders
Over £599.95 Ex-Vat

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Contact us on 0300 303 4578
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Knauf Insulation Rocksilk® RS80 Rock Mineral Wool Slabs: Advanced Insulation for Enhanced Thermal and Acoustic Performance


Elevate the efficiency of your projects with Knauf Insulation Rocksilk® RS80, a high-density rock mineral wool slab that excels in thermal insulation, fire protection, and acoustic applications.

With a density of 80 kg/m³ and a thermal conductivity of 0.034 W/mK, Rocksilk® RS80 provides superior insulation performance. Manufactured using sustainable ECOSE® Technology, it meets the highest safety standards with a Euroclass A1 fire classification.

Key Benefits

  • High-Density Insulation: The 80 kg/m³ density ensures excellent thermal and acoustic insulation properties, making it ideal for demanding environments.
  • Superior Fire Resistance: Withstands temperatures over 1000°C, offering enhanced fire safety over extended periods.
  • Versatile Application: Perfect for ground floors, internal and separating floors, pitched roofs, internal walls, and more, providing a flexible solution for various construction needs.

Available Sizes

Thickness Thermal Resistance Length Width Slabs Per Pack
50mm 1.45m2K/W 1200mm 600mm 6
75mm 2.20m2K/W 1200mm 600mm 4
100mm 2.90m2K/W 1200mm 600mm 3

Product Specifications

Specification Value
Thermal Conductivity  0.034W/mK
Fire Classification A1
Generic BRE Green Guide Rating A+
Vapour Resistivity 5.00 MNs/g.m
Material Rock Mineral Wool
Density 80 kg/m3


  • Ground and Internal Floors: Improves thermal comfort and energy efficiency.
  • Separating Floors: Enhances sound reduction between different levels of buildings.
  • Pitched Roofs and Rafter Levels: Offers robust thermal resistance, crucial for temperature regulation.
  • Internal Walls/Partitions: Ideal for reducing noise transmission and enhancing privacy within spaces.
  • Light Steel and Timber Frame Walls: Provides critical insulation while maintaining structural integrity.

Frequently Asked Questions (FAQs)

What is Knauf Insulation Rocksilk® RS80?

Knauf Insulation Rocksilk® RS80 is a high-density rock mineral wool slab that offers superior thermal insulation, acoustic control, and fire protection, ideal for various building applications.

What is the difference between Knauf Insulation Rocksilk® RS45, RS60, RS80, RS100 and RS140?

The Knauf Insulation Rocksilk® RS range consists of mineral wool slabs that differ primarily in density, which affects their thermal and acoustic insulation properties. The RS45, RS60, RS80, RS100, and RS140 are all designed for various applications but vary by density and, consequently, by their specific use-cases:

  • RS45 has a density of 45 kg/m3, making it suitable for a broad range of general applications where moderate insulation is needed.
  • RS60 has a density of 60 kg/m3, offering enhanced thermal and acoustic performance suitable for more demanding environments.
  • RS80 and RS100 increase in density and are typically used where higher performance insulation is necessary, such as in industrial applications or where superior fire resistance is required.
  • RS140 has the highest density at 140 kg/m3, providing the maximum level of insulation and fire protection, making it ideal for specialized applications needing the highest performance material.

Each slab type is also available in various thicknesses to accommodate different requirements, ensuring versatility across a range of construction scenarios.

How does Rocksilk® RS80 improve thermal performance?

With a thermal conductivity of 0.034 W/mK, Rocksilk® RS80 provides excellent insulation, helping to maintain consistent indoor temperatures and reduce energy costs.

What makes Rocksilk® RS80 suitable for fire protection?

Rocksilk® RS80 is non-combustible and meets the Euroclass A1 fire classification, ensuring it does not contribute to the spread of fire, thereby enhancing building safety.

Can Rocksilk® RS80 be used for acoustic insulation?

Yes, the high density of Rocksilk® RS80 makes it highly effective at sound absorption and reduction, making it ideal for use in environments where noise reduction is crucial.

What are the environmental benefits of using Rocksilk® RS80?

Rocksilk® RS80 is manufactured using Knauf's ECOSE® Technology, a sustainable bio-based binder that is free from formaldehyde, phenols, and dyes, making it more environmentally friendly than traditional insulations.

Is Rocksilk® RS80 easy to install?

Yes, Rocksilk® RS80 is designed for easy installation. It can be cut to fit various spaces and is flexible enough to install in hard-to-reach areas, simplifying the installation process across a range of applications.

Data Sheet


Order Value Delivery Charge
Up to £200.00 ex-vat £100.00 ex-vat
£200.00 - £599.95 ex-vat £59.95 ex-vat
Above £599.95 ex-vat Free Delivery


Weekend Delivery
Available upon request


Parcel Rates
Delivery charge may vary depending on quantity and volume of your order.
Pricing will be calculated during checkout.


Local Delivery Charge
Within 35 miles of Postcode S63 9BL - Up to £500.00 ex-vat
Delivery Charge £35.00 ex-vat
Please contact us to arrange collections
Tel: 0300 303 4578 | Email:


Delivery charges will automatically be calculated within the checkout process.
Orders are only processed for delivery between 8.00am - 5.00pm Monday to Friday excluding bank holidays.
Moffett offload will be used for large bulky deliveries and only when agreed with you.
Please advise of any access issues on ordering.
Delivery is Kerbside only.
In the unlikely event that your delivery is not correct or damaged please notify us immediately and mark any issues on the delivery slip.


    Where We Deliver

    Delivery Areas

    We have a fleet of FORS delivery vehicles all with Moffett mechanical off loads that deliver nationwide. Sometimes we may use 3rd party carriers for smaller orders.


      Product Delivery Times

      The vast majority of our orders are dispatched within 3 working days, this can however be up to 5 working days, please contact us if you require something urgent.
      Speciality items may take up to 5-7 working days.
      We will contact you with in 24/48hrs of your order been placed to confirm delivery times and dates.

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