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Thermafleece CosyWool Sheep's Wool

CosyWool - Natural Sheep's Wool offers excellent thermal and acoustic performance

Enjoy the full benefit of sheep’s wool insulation with its enhanced performance, durability and sustainability
  • Thermafleece CosyWool is a versatile product designed for use in most applications within the building envelope.
    Applications include cold and warm roof, timber frame and solid wall, and all floor levels above DPC
  • Thermafleece CosyWool roll, is readily available with short lead-times
  • The CosyWool Range includes the following product thickness's 50mm, 75mm, 100mm, and 150mm
  • Product widths of both 370mm and 570mm, designed to complement joist spacings of 400mm and 600mm centres respectively
  • Thermafleece wins 'Best for Natural & Sustainable Insulation 2016' & 'Most Innovative Natural Wool Insulation Product' in Build Magazine. Sustainable Building Awards 2016 are focused on rewarding the efforts of the individuals and firms who have helped shape the world of Eco-friendly and Sustainable buildings across the globe
  • CosyWool slabs are also available – contact us to discuss your requirements

  • Delivery charges of £45.00 + VAT apply per order of Thermafleece products (CosyWool and/or Supaloft)
    Please read the delivery terms and conditions before placing your order
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Ecotherm manufacture both general purpose and application specific Rigid PIR Boards


Thermafleece CosyWool Insulation Rolls

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Cosywool natural insulation

Thermafleece CosyWool is a versatile natural sheep's wool insulation product designed for use in most applications within the building envelope. Applications include cold and warm roof, timber frame and solid wall, and all floor levels above DPC

Our Prices are currently being revised please contact us for the latest prices


Thermafleece Product Applications

Rich in British wool - easy to install between and over joists, ideal for floors and lofts
Insulating a property will significantly reduce the amount of energy lost from the building envelope, thereby reducing energy consumption and carbon dioxide released to the atmosphere.

  • Roofs – Loft & warm roof
  • Walls – Timber frame & solid (internal)
  • Floors – All levels above DPC
  • Acoustic – Walls, floors & roofs


Thermafleece CosyWool Product Details

Thermafleece CosyWool Roll's convenient compressed form reduces transport impacts by more than 50% compared to other natural insulation and makes it ideal for quick and easy installation. Once unpacked, it regains its original thickness to provide excellent thermal and acoustic performance.

Product Benefits

  • Thermal Conductivity: 0.039 Wm-1K-1
  • Density: 18 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

Product Characteristics

  • Eco-Friendly Product containing recycled Natural Sheep's Wool
  • Dimensions = Length: Varies relative to the Roll Thickness - Width: 3 x 370mm 1110mm  or 2 x 570mm = 1140mm
  • Performance related to selected applications ...

  • Loft - between and over joists
    CosyWool 0.039 W/mK Insulation Depth (mm)
    Between Joist Over Joist Total depth U-Value W/m²K
    100 140 240 0.16
    100 200 300 0.13

    Pitched roof between and under rafters
    CosyWool 0.039 W/mK Insulation Depth (mm)
    Between Rafters Under rafters Total depth U-Value W/m²K
    150 75 225 0.18

    Flat roof - between and under joists
    CosyWool 0.039 W/mK Insulation Depth (mm)
    Between Joist Under Joist Total depth U-Value W/m²K
    150 75 225 0.17

    Timber frame - between studs
    CosyWool 0.039 W/mK Insulation Depth (mm)
    Between Stud Cross Batten Total depth U-Value W/m²K
    150 0 150 0.28
    150 50 200 0.18

    Timber frame - between studs with 25mm low emissivity void
    CosyWool 0.039 W/mK Insulation Depth (mm)
    Between Stud Low-E void Total depth U-Value W/m²K
    100 25 100 0.26
    150 25 150 0.2

Product Information

Thermafleece CosyWool datasheet | Thermafleece CosyWool Roof Application | Thermafleece CosyWool Floor Application | Thermafleece CosyWool Wall Application | Thermafleece CosyWool for Acoustic Partition Walls | Thermafleece CosyWool Indoor Air Quality | Thermafleece CosyWool U-Values


Product Installation

Thermafleece CosyWool does not irritate skin, eyes or the respiratory tract, thus can be installed without gloves or protective clothing, however, it is recommended to wear a dust mask in enclosed spaces.

Loft: Cold roof

  • Lay the first layer of insulation between the joists ensuring all joints are close-butted to avoid air gaps. Cross-lay additional layers of insulation on top of the joists.
  • Where a low vapour resistance membrane is used, take insulation over the wall plate to meet the wall insulation and push tight against the breather membrane. Refer to the membrane manufacturer for guidance on eaves ventilation.
  • Where a high vapour resistance membrane is used, eaves ventilators are required. Care must be taken to avoid blocking the ventilation air path.
  • Thermafleece can also be used to insulate the floor of a boarded loft space. Fit the first layer between joists ensuring all joints are close-butted to avoid air gaps. Fit additional layers of Thermafleece between cross laid joists ensuring all joints are close-butted to avoid air gaps.
  • Insulation should not be fitted between joists under water tanks. Additional layers of insulation should be installed along the sides of the tank to meet the lagging around the tank.
  • Down-light covers that meet Part F and Part B of the Building Regulations should be used where appropriate.

Loft: Warm roof

  • Fit insulation under the roofing membrane.  Counter battens and tiles can remain in place
  • during installation. Installation will depend on the type of roofing membrane used.
  • By using a low vapour resistance membrane, the insulation can fully fill the rafter space without the need for ventilation above the insulation.
  • When using a high vapour resistance membrane leave a ventilation space between the insulation and the membrane. Ensure a 50mm continuous ventilation opening at every rafter spacing and 25mm at the eaves with 5mm continuous gap each side of the ridge.
  • If a higher insulation performance is required, additional insulation can be installed under the rafters by fixing a counter batten against the underside of the timber rafter and cross-laying Thermafleece between the battens.

Between Floors

  • Thermafleece can be easily installed between joists to provide additional thermal insulation and acoustic absorption within the structure. Thermafleece is available in thicknesses to enable insulation to fill or partially fill the void.
  • Fit the insulation layers between the joists ensuring all joints are close-butted to avoid air gaps. Overlap additional layers to reduce thermal bridging and air gaps. The friction of the insulation should hold it in place. However, if insulation is installed from below, you can hold it in place using string or netting until the ceiling layers are secured. As with other insulation products, it may be necessary in some cases to de-rate electrical cables buried in insulation. BS 7671: 2008 suggests that where wiring is completely surrounded by insulation, it may need to be de-rated to as low as half its free air current carrying capacity. Guidance should be sought from a qualified electrician.

Suspended Ground Floors

  • Thermafleece is an ideal choice for helping minimise heat loss through suspended floors. Fit the insulation layers between the joists ensuring all joints are close-butted to avoid air gaps. Overlap additional layers to reduce thermal bridging and air gaps. Support insulation with netting or plywood to the underside of the joist. An airtight breather membrane can be fitted to the underside of the joist to minimise air movement through the floor.
  • If the flooring comprises open floorboards, you could install a breather membrane on the top side of the Thermafleece to avoid a build-up of dust and debris on top of the insulation. Maintain a ventilated space at least 150mm below the level of the insulation. Ensure that all air vents under the floor are unobstructed and take care not to block ventilation air path.

Solid Walls

  • Thermafleece can be used as part of a system to internally insulate solid walls reducing energy loss in otherwise hard to heat properties. Thermafleece can be securely fitted between studwork to full-fill or part-fill the void.
  • Fit a breather membrane to the inner face of the solid wall on the cold side of the insulation and fit a vapour control layer to the warm side before installing the wall finishing.
  • Fit the insulation layers between studs ensuring all joints are close-butted to avoid air gaps. Overlap additional layers to reduce thermal bridging and air gaps. The friction of the insulation will hold it in place.
  • A service void can be created by counter battening along the timber frame and fixing an internal lining board. This ensures that the insulation remains undisturbed and airtightness remains intact when services are accessed for maintenance.
  • The insulation performance of the void can be improved by replacing the VCL with a Low Emissivity Membrane.

Standard Timber Frame Wall

  • A standard timber frame construction incorporates a 140mm timber stud with a 9mm racking board attached to the outer leaf to form a structural wall system.
  • All internal load-bearing and non load-bearing walls are constructed using an 89mm timber stud.
  • Fix VCL to the warm side of the insulation to reduce the risk of interstitial condensation. The addition of vapour impermeable materials must be correctly detailed and materials must be completely sealed to ensure that no moisture can penetrate into the structure.
  • Thermafleece can be used to fill the wall void as part of a system to comply with Part L of the Building Regulations.

Twin Timber Frame Wall

  • Twin frame systems utilise two standard 89mm timber studs to allow a deeper timber frame that can insulated to a greater thickness.
  • The twin frame system ensures that reduced thermal bridging occurs within the construction helping maximise insulation performance. By using two 89mm structural timber frames, the width of the construction can be varied to achieve specific insulation performance.

Breathing Timber Frame Wall

  • Breathing timber frame wall systems incorporate a standard timber frame structure in conjunction with an external natural fibre insulation board. Thermafleece should be fitted between studs before the external components are installed. This provides a complete breathing wall structure without relying on breather membranes or internal vapour controls.
  • Unlike traditional timber frame systems, the racking board is positioned to the inside of the timber frame. The external insulation attached to the timber frame maintains the frame above the dewpoint temperature reducing the risk of condensation. Additional benefits include low environmental impact, lightweight structure and improved insulation and airtightness.

“I” Beam Timber Frame Wall

  • The timber ‘I’ beam system is used to create a greater depth of timber frame which can be filled with a greater quantity of insulation. The structural timber frame ‘I’ beam section has a racking board attached to the cavity side of the construction to give a high degree of strength. The system can also be fabricated as a closed panel system, delivered to site in sections that can be pre-insulated with the Thermafleece.
  • A service void can be created by counter battening along the timber frame internal face and fixing the internal finishing board. This ensures that the insulation remains undisturbed and airtightness remains intact when services are accessed for maintenance. The insulation performance of the void can be improved by installing an Eden Low Emissivity Membrane against the insulation.
  • As with other insulation products, it may be necessary to de-rate electrical cables buried in insulation. BS 7671: 2008 suggests that where wiring is completely surrounded by insulation, it may need to be de-rated to as low as half its free air current carrying capacity. Guidance should be sought from a qualified electrician.

Cutting

  • Thermafleece CosyWool roll can be cut using a straight edge and a Stanley knife, or simply torn apart.
  • For more accurate cutting, tightly compress or clamp 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.
  • For accurate cutting, tightly compress or clamp the insulation between two pieces of solid 15mm board. Overhang the slab where you want to cut keeping the two board edges aligned. Cut the edge with a scalloped edged knife and keep the blade firm and square against both board edges throughout.

Storage

  • Protect the insulation from prolonged exposure to sunlight when unpacked and avoid wetting for extended periods, store under cover and clear of the ground.

Contact Us

Address:
27 Massetts Road, Horley,
Surrey, RH6 7DQ, UK.

About Us

Our mission is to bring our customers the very best products at the very best prices. Due to our high volume of sales, we have  negotiated levels of pricing with the Manufacturers or their Distributors that are normally reserved for their very largest business accounts.

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