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 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.

Have you seen our newly released colour match fixings for Rocksilk® Soffit Linerboard? Ask your sales rep today for more information.


  • 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 Classification Facing
130/6 1200 600 0.034 / 0.24 3.95 A1 Faced
160/6 1200 600 0.034 / 0.24 4.80 A1 Faced
185/6 1200 600 0.034 / 0.24 5.55 A1 Faced
220/6 1200 600 0.034 / 0.24 6.55 A1 Faced

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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