Rock Mineral Wool - Knauf Insulation Rocksilk® Soffit Linerboard Extra

Knauf Insulation Rocksilk® Soffit Linerboard Extra


Exposed soffit floors


Rock Mineral Wool


Rocksilk® Soffit Linerboard Extra is a Rock Mineral Wool slab with a non-combustible facing board, designed to insulate structural soffits in semi-exposed environments such as open-sided car parks.

It is non-combustible with the best possible Euroclass A1 reaction to fire classification, and is manufactured using Knauf Insulation's unique bio-based binder, ECOSE® Technology.


  • Impact resistant fibre cement flat sheet ideal for semi exposed environments.
  • Provides a solution to upgrade thermal performance of existing floors without reducing floor height.
  • Can be installed without the need to access areas above the floor.



Thickness (mm)Length (mm)Width (mm)Thermal Conductivity (W/mK)R-Value (M²K/W)Euroclass Reaction to Fire ClassificationFacing
130/612006000.034 / 0.243.95A1Faced
160/612006000.034 / 0.244.80A1Faced
185/612006000.034 / 0.245.55A1Faced
220/612006000.034 / 0.246.55A1Faced

Certification & Memberships

Eurofins Gold
Euroclass A1 Reaction to Fire Classification
CE Marking
Green Guide Rating A
EN 15804


We care for the people who make our products, the people who use them and the world we all depend on.

 Whilst we are dedicated to supplying sustainable high performance insulation solutions for enhanced energy efficiency in buildings, we also continually strive for improvements in our manufacturing and supply chain operations so to improve quality and minimise our impact on the environment. All Knauf Insulation production locations have state-of-the-art manufacturing equipment and meet the highest quality standards as well as they are supported by an ongoing research and development program. All of our products including Knauf Insulation Rocksilk® Soffit Linerboard Extra are sustainably manufactured.

At Knauf Insulation, we have 7 key sustainability considerations:

  • to conserve natural resources
  • to reduce the evironmental effects of our own processes
  • Treating people fairly, along the supply chain
  • Delivering our products efficiently
  • Building a comfortable and healthy indoor environment
  • Performance reporting
  • Recognition
ECOSE® Technology

ECOSE® Technology is our revolutionary sustainable bio-based binder used in the manufacture of all of our glass mineral wool products, and the majority of our rock mineral wool products. invented nearly 10 years ago, it is not only unique, but very much central to our sustainability strategy.  Our ECOSE® Technology is present in Knauf Insulation Rocksilk® Soffit Linerboard Extra and is just another key benefit of our products.

ECOSE® Technology has 5 key benefits

  • A natural binder
  • A lower embodied energy
  • Proven durability
  • Optimum indoor air comfort
  • Easy to handle

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