Rock Mineral Wool - Rocksilk Krimpact Flat Roof Slab Extra


Flat roof


Rock Mineral Wool


Rocksilk Krimpact Flat Roof Slabs are high strength, dense rigid slabs made from Rock Mineral Wool, manufactured using Krimpact technology, specifically designed for use in flat roofing applications.

Products are available in two grades:

  • Rocksilk Krimpact Flat Roof Slab and;
  • Rocksilk Krimpact Flat Roof Slab Extra. 

Rocksilk Krimpact Flat Roof Slab Extra is manufactured with a higher density than Rocksilk Krimpact Flat Roof Slab Standard to provide a higher level of compressive strength for use in flat roofs requiring long term compression performance.

Slabs contain a special additive to ensure their water repellency.


  • Non-combustible Euroclass A1 Reaction to Fire rating
  • Excellent acoustic insulation
  • Superior compression strength



Thickness (mm)Thermal Conductivity (W/mK)R-Value (M²K/W)Euroclass Reaction to Fire ClassificationLength (mm)Width (mm)Area Per Pallet (m²)


BBA Certificate 08_4526 Rocksilk Krimpact Flat Roof Slab
Eurofins Gold
A1 Euroclass Fire Rating
CE Marking
Bureau Veritas
Green Guide Rating B-C

Additional Product Information


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 Rocksilk Krimpact 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