Thermafleece CosyWool – Sheep's Wool Flexible Slab Insulation
Thermafleece CosyWool – Sheep's Wool Flexible Slab

Key Facts

  • Width (mm) – 390, 590
  • Thickness (mm) – 50, 75, 100, 140
  • Thermal Conductivity – 0.038 W/mK
  • Highly Breathable
  • Made in the UK
  • Contains British Wool
  • Manufactured to ISO 9001 & 14001
  • Can be recycled

Thermafleece CosyWool – Sheep's Wool Flexible Slab

Thermafleece CosyWool slab is a versatile insulation made from 75% British sheep's wool. and 25% recycled polyester  A great choice for insulating walls and roofs. Research shows that using 75% wool in combination with recycled fibres outperforms alternative products with a higher percentage of wool. Our wool rich blend ensures you get the full benefit of sheep’s wool with enhanced performance, breathability, durability and sustainability.

CosyWool Slabs are flexible but denser than rolls and sized to provide extra tight friction fit in walls and roofs providing excellent thermal and acoustic performance.

Installing Thermafleece

Thermafleece CosyWool flexible slabs are harmless and can be installed without gloves or protective clothing, although we recommend you wear a dust mask in enclosed spaces such as lofts.  Thermafleece CosyWool is not irritating to the skin, eyes or respiratory tract.

To retain the benefits of water vapour, absorption and release, Thermafleece CosyWool  flexible slabs may be used in conjunction with a vapour permeable underlay. Protect the insulation from prolonged exposure to sunlight when unpacked and avoid wetting for extended periods, store under cover and clear of the ground.

Cutting Tips

Thermafleece can be safely and easliy torn apart, but if you need a more accurate edge then we recommend the 'Roll and Cut' Method

Tools Required: Sharp Scalloped Edge Knife or Insulation Saw

1. For an accurate length, take the insulation and  roll it as tightly as possible along the width. Measure where you need to cut then taking the insulation saw / knife  easily cut through. This provides a nice, neat edge and is an alternative to tearing by hand.
2. To cut the width of the slab: Roll the insulation tightly along the length and secure. Measure the required width that you need then using the knife or insulation saw begin to cut through the whole roll.  

Take a look at the video on YouTube or download the How To Cut Application notes

You can also cut Thermafleece by tightly compressing or clamping the insulation between two pieces of solid 15mm board. Overhang the fleece where you want to cut keeping the two board edges aligned. Saw cut the edge using a sharp, scalloped edged knife and keep the blade firm and square against both board edges throughout. Trim any fine remaining fibres with large scissors or shears.


  • Thermal Conductivity: 0.038 Wm-1K-1
  • Density: 22 kgm-3
  • Water Absorption (@100% RH): 30% w/w
  • Specific Heat Capacity: 1800 Jkg-1K-1
  • Mould Resistance: CUAP 2002-01-25: Pass
  • Moth/Beetle Proofing: ISO 3998: Pass
  • Vapour Resistivity: 9 MN·s·g-1m-1
  • Ignition Point: >500oC
  • Spread of Fire to BS 5803-4: Pass
  • Recoverability and thickness, EN 823: Pass
  • Dimensional stability to EN 1604: Pass
  • Can be used to achieve airborne sound reduction of Rw = 40dB
  • GWP (Cradle to Gate): minus 0.2 kgCO2e
  • Embodied Energy (Net of Non-Fossil Feedstock Energy): 7 MJkg-1
  • Recycled Content: 20%
  • Recyclable: Yes

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