Knauf Rocksilk® RS140 Building Slab | 1200mm x 600mm | All Sizes

KnaufSKU: IUK01679

Sale price£49.09 

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

Need something quicker?

Contact us on 0300 303 4578
or email here!

Knauf Insulation Rocksilk® RS140 Rock Mineral Wool Slabs: Premium Insulation for Enhanced Fire Protection and Acoustic Performance


Elevate the safety and efficiency of your construction projects with Knauf Insulation Rocksilk® RS140, a superior rock mineral wool slab known for its high density of 140 kg/m³ and a thermal conductivity of 0.034 W/mK. 

This slab is designed not only for thermal and acoustic insulation but also for advanced fire protection applications, making it an ideal choice for high-risk areas.

Key Features

  • Multipurpose Use: Knauf Insulation Rocksilk® RS140 is ideal for various applications across residential, commercial, and industrial sectors.
  • Enhanced Density: With a density of 140 kg/m³, Rocksilk® RS140 provides robust insulation and is particularly effective in fire protection applications.
  • Superior Fire Resistance: Meets the highest standards with Euroclass A1 fire classification, offering exceptional protection against fire.
  • Acoustic Control: Excellent for reducing noise transmission, enhancing comfort in both residential and commercial settings.

Available Sizes

Thickness Thermal Resistance Length Width Slabs Per Pack
50mm 01.45m2K/W 1200mm 600mm 4
75mm 2.20m2K/W 1200mm 600mm 3
100mm 2.90m2K/W 1200mm 600mm 2

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 140 kg/m3


  • Floor Insulation: Rocksilk® RS140 is perfect for insulating ground and internal floors, improving comfort and energy conservation.
  • Acoustic Barriers: Ideal for separating floors in multi-story buildings, Knauf Rocksilk® RS140 enhances privacy and noise control.
  • Thermal Insulation: Effective in pitched roofs at rafter level, Knauf Rocksilk® RS140 maintains consistent temperatures and reduces energy costs.
  • Partition Insulation: Use Rocksilk® RS140 for internal walls and partitions to create quieter, more private spaces.
  • Structural Insulation: Ideal for light steel and timber frame walls, Knauf Rocksilk® RS140 supports structural integrity while providing excellent insulation.

Frequently Asked Questions (FAQs) about Knauf Insulation Rocksilk® RS140

What is Knauf Insulation Rocksilk® RS140 used for?

Knauf Insulation Rocksilk® RS140 is a high-density rock mineral wool slab designed for advanced thermal insulation, superior acoustic performance, and enhanced fire protection applications in both commercial and residential buildings.

How does Knauf Insulation Rocksilk® RS140 enhance fire safety?

Knauf Insulation Rocksilk® RS140, with its high density of 140 kg/m³ and Euroclass A1 fire rating, provides robust protection against fire, making it suitable for high-risk fire protection applications.

What makes Knauf Insulation Rocksilk® RS140 different from other insulation materials?

The exceptional density of Knauf Insulation Rocksilk® RS140 not only offers improved thermal and acoustic insulation but also makes it highly effective for fire protection applications, setting it apart from lower density insulants.

Can Knauf Insulation Rocksilk® RS140 be used in residential projects?

Yes, Knauf Insulation Rocksilk® RS140 is ideal for residential projects requiring high-performance insulation that offers additional benefits such as superior fire resistance and excellent soundproofing capabilities.

Is Knauf Insulation Rocksilk® RS140 environmentally friendly?

Knauf Insulation Rocksilk® RS140 is manufactured using ECOSE® Technology, a sustainable, bio-based binder that reduces environmental impact, making it a greener choice for insulation.


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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