Rockwool Flexi Slab 1.2m x 600mm

  • Size of rolls: 600 x 1200mm
  • Excellent thermal, acoustic and fire insulation
  • Suitable for application between timber and steel frames
  • Non-combustible
  • Water repellent
  • Patented flexible edge
  • Rockwool Flexi Slabs are sold per pack

Rockwool Flexi Slab 

Rockwool Flexi Slabs are intended for a wide range of building applications. It is a multi-use, dual-purpose acoustic and thermal mineral wool insulation slab with a flexible edge along one side which ensures a perfect fit is maintained between the insulation and the supporting framework. This patented technology helps to prevent insulation shrinkage, thereby significantly reducing cold spots. The insulation can be fitted between fresh timber and will expand into the wider space as the timber shrinks back. Ideal for separating walls and floors, framed external walls, framed internal partitions and pitched roofs.

Rockwool, also known as mineral wool, is very similar to fibreglass. Made from molten volcanic rocks, the material is produced by heating the volcanic rock within a large furnace, then spinning it into fibrous strands and compressing it into boards. As a vapour-permeable, A1 noncombustible insulation material, Rockwool is the insulation material of choice for architects and builders alike.

Rockwool products achieve a Euroclass A1 classification for non-combustibility – this is the highest rating that an insulation material can achieve. The safest insulation material on the market, Rockwool Flexi Slabs actively prevent the spread of flames in the event of a fire and can withstand temperatures of up to 1,000ºC (1,800ºF). The open porous structure of the stone wool means that the boards are also able to absorb and reduce the impact of sound, enabling homeowners to enjoy a comfortable, quiet internal environment. This is ideal for both the commercial and domestic sectors.

Flexi Slabs offer all-round performance with their robust form and water repellent qualities. They are available in a wide range of thicknesses and are very easy to handle and install.

Technical specification

  • Composition: mineral wool
  • Thermal conductivity: 0.035W/mK
  • Reaction to fire: Euroclass A1
  • Size of boards: 600 x 1200mm
  • Density: 33kg/m3
  • Weight: 15.12kg
  • Weight/m2: 1.65kg
  • R-Value: 1.32W/m2K
  • Thicknesses available: 50mm, 75mm, 90mm, 100mm, 140mm

Coverage per pack

Thickness (mm) Boards per pack M2 per pack
50 12 8.64
70 8 5.76
90 6 4.32
100 6 4.32
140 4 2.88


Rockwool Flexi Slab should be installed in accordance with the manufacturer’s installation guidelines – these should cover design and all aspects of the application of the insulation. 


Shelf life: please see the manufacturer’s date of expiry. Keep in a dry place, in the original packaging. Avoid excess heat or UV light exposure.


50mm – 8.64m2, 70mm – 5.76m2, 90mm – 4.32m2, 100mm – 4.32m2, 140mm – 2.88m2


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