Rock Mineral Wool - Knauf Insulation Rocksilk® Soffit Linerboard Extra

Knauf Insulation Rocksilk® Soffit Linerboard Extra


Structural soffit floor


Rock Mineral Wool


Rocksilk® Soffit Linerboard Extra is a rock mineral wool slab with an impact-resistant cementitious 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 our unique bio-based binder, ECOSE® Technology.


  • Impact-resistant, cementitious facing board 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.
  • Manufactured from mineral wool which provides the best levels of sound absorption and reduction compared to other mainstream insulants to reduce the sound transfer between storeys.
  • Available with optional fixings which match the colour of Rocksilk® Soffit Linerboard Standard and Extra.

For historical versions of product documentation, or documents relating to any discontinued products, please contact us with your requirements at [email protected].  



Thickness (mm) Length (mm) Width (mm) Thermal Conductivity (W/mK) R-value (m²K/W) Euroclass Reaction to Fire Classification
130/6 1200 600 0.034 / 0.24 3.95 A1
160/6 1200 600 0.034 / 0.24 4.80 A1
185/6 1200 600 0.034 / 0.24 5.55 A1
220/6 1200 600 0.034 / 0.24 6.55 A1

Certification & Memberships

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


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