Rock Mineral Wool - Knauf Insulation Rocksilk® Flat Roof Slab Extra

Knauf Insulation Rocksilk® Flat Roof Slab Extra


Flat roof


Rock Mineral Wool


Rocksilk® Flat Roof Slab Extra is a BBA certified Rock Mineral Wool slab with the strongest mechanical performance in the range, designed for use in mechanically fixed flat roof build ups onto all types of roof deck.

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


  • Slabs contain a special additive to ensure their water repellency.
  • Manufactured using Knauf Insulation's Krimpact® Technology for high levels of compressive strength and durability.
  • Excellent sound absorption and reduction characteristics.



Thickness (mm)Length (mm)Width (mm)Thermal Conductivity (W/mK)R-Value (M²K/W)Euroclass Reaction to Fire ClassificationFacing

Certification & Memberships

BBA Certificate 08_4526 Rocksilk Krimpact Flat Roof Slab
Eurofins Gold
Euroclass A1 Reaction to Fire Classification
CE Marking
EN 15804
Made in Britain


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® Flat Roof Slab 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