Since pioneering the UK’s first British sheep’s wool insulation in 2000, Thermafleece has remained the UK’s leading brand by putting quality, performance, and the planet first.
When you choose us, you’re backed by a small, deeply experienced team committed to first-class service. From quick order processing to technical advice, we’re here to help with enquiries of any size.
We are Eden Renewable Innovations Ltd (ERI), a privately owned company based in the heart of the Lake District UNESCO World Heritage Site. Operating within this landscape allows us to see firsthand the power of nature. It serves as a daily reminder of why we must make the best use of our homegrown resources.
This stunning environment is also a working landscape. Our deep connection to the generations of hill farmers that have shaped the fells naturally roots our identity in British agriculture. By sourcing British wool, we don’t just create sustainable products; we directly support the farming communities that care for our countryside.
To understand our mission, you have to understand the people behind it. Our work is driven by the combined expertise of our owners, Christine Armstrong & Mark Lynn, who have worked side-by-side for over 20 years.
The Heritage: Christine’s roots are in the land; she comes from a long line of local sheep farmers.
The Science: Mark is a chemist with a specialist focus on natural materials and building physics.
Together, they have created a perfect synergy of agricultural tradition and modern scientific innovation. This unique perspective is shared by our entire team, all of whom are dedicated to running an ethical business that values our social and environmental responsibilities in equal measure.
Constant Innovation: From our flagship CosyWool to our high-density UltraWool, we have spent 25 years perfecting how natural fibres protect your home.
We believe buildings should work in harmony with the people inside them. We chose wool because it is nature’s “super-fibre”— it breathes, naturally purifies the air, and creates healthier living spaces.
Constant Innovation: From our flagship CosyWool to our high-density UltraWool, we’ve spent 25 years perfecting how natural fibres protect your home.
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Supporting British Farming: As proud licensees of British Wool, we source locally and manufacture in Yorkshire. This supports our farming community and keeps our carbon footprint to a minimum.
Prioritising Health: Our products aren’t just about warmth; they are designed to reduce energy use and enhance the long-term structural health of your building.
To us, sustainability isn’t a marketing buzzword; it’s a measurable commitment. We believe in being held accountable, which is why we manage our carbon reduction strategy through the ISO 14001 framework.
We also provide third-party verified EPDs (Environmental Product Declarations). This ensures you have the hard data to see the environmental impact of our products from cradle to grave.
We know that choosing insulation is a significant decision. Whether you need deep technical support or simple, honest guidance, our team is here for you. Our advice is backed by decades of expertise and a genuine desire to help you build a more sustainable future.
Thermafleece is so versatile it’s been used in properties of all shapes, sizes and ages. Take a look at the variety of properties that have used Thermafleece over the last 25 years.
We believe buildings should work in harmony with the people inside them. We chose wool because it is nature’s “super-fibre”—it breathes, naturally purifies the air, and creates healthier living spaces.
We’ve compiled a list of the most common inquiries to help you get the information you need quickly. If you can’t find what you’re looking for, please get in touch.
Yes. It is non-itchy, safe to handle, and can be installed by homeowners. UltraWool friction-fits between rafters and studs, while CosyWool is ideal for laying between and over joists in lofts and floors. CosyWool also friction fits but this is not so important for horizontal applications.
Download our product factsheets here
While both materials are great for sound absorption, Thermafleece offers distinct advantages over mineral fibre like fibreglass and rockwool. Unlike mineral fibre, Thermafleece actively buffers humidity to reduce the risk of condensation, naturally absorbs indoor pollutants like formaldehyde, and carries a lower carbon footprint.
While mineral fibre is cheaper upfront, the long-term energy savings of Thermafleece make the lifetime cost difference negligible.
Thermafleece is suitable for most standard building applications, though mineral fibre remains necessary where non-combustible fire ratings are necessary.
Truly breathable insulation must be vapour-open and also be able to buffer moisture. Thermafleece absorbs and releases moisture to help manage humidity levels and maintain the structural health of the building fabric.
Read more about breathability here
It is important to take the time to calculate how much insulation you need to ensure the best fit and avoid over or under-ordering. Planning the installation is an important part of the job, and correctly installed insulation will significantly improve thermal performance.
Tools Required: Sharp Scalloped Edge Knife or Insulation Saw.
While it can be torn by hand, the recommended “Roll and Cut Method” provides a neater edge. This involves rolling the insulation tightly and cutting through the roll with a sharp scalloped edge knife or insulation saw.
FOR AN ACCURATE LENGTH: If you have a slab or a roll and want an accurate length, take the insulation and roll it as tightly as possible along the width. Measure where you need to cut to give you the length you require. Taking the insulation saw / knife easily cut through. This provides a nice, neat edge and is an alternative to tearing by hand.
TO CUT THE WIDTH OF THE ROLL: Tightly roll a length of insulation, typically up to 2.5m. Keep the insulation rolled and do not unwind. Measure the required width that you need then using the knife or insulation saw begin to cut through the whole roll.
Both CosyWool and UltraWool contain 75% British wool, 15% recycled polyester loft agent, and 10% polyester binder. The recycled polyester helps create a ‘bouncier insulation’ that enables us to compress pack and the binder provides strength and durability. The polyester does not affect the breathability of the insulation.
Thermafleece is an excellent insulation product that makes great use of British wool. It offers excellent thermal performance while allowing the building to breathe, helping us meet building regulations. Installation was quick, simple and safe, with no fuss.
We are great fans of Thermafleece CosyWool sheep’s wool insulation & have used it for approximately 20yrs. It is so much more than a quilt insulation. It’s ability to control vapour within a structure is outstanding. Plus it’s so nice to handle!
The thermafleece cosywool sheep’s wool insulation was amazing to work with and very easy to lay. We noticed the difference immediately and are super pleased with its performance so far. Service from ordering to delivery was excellent.
Meets all insulation and regulation requirements beautifully. So much better than other man made alternatives. So much better to install. Far more healthy from many angles – especially installation – no irritating particles.
My loft was insulated with fibreglass, which required me to wear a face mask when entering the loft, and I needed to replace it.
As a sheep farmer, I looked into using sheep’s wool. I thought that this was the right thing to do environmentally, “walk the
UltraWool is an excellent sustainable product. Being sourced and manufactured in the UK helped reduce our project’s carbon footprint, and it was safe and easy to install without the need for special protective equipment.
Lovely to be using a natural product. Not sure we had the right tools to cut it, but managed with scissors and persistence! Used to insulate the summer house in the garden – feels very cosy in there now.
Insulating with UltraWool signigicantly reduces the amount of energy lost from the building envelope, reducing energy consumption and carbon dioxide released to the atmosphere
Breathable natural fibres contribute to a more stable humidity and moisture lev
Felt the Difference all most right away.
Beyond its fantastic and self-evident insulative properties, the most remarkable thing for us was how pleasant Thermfleece insulation was to use. It turned the job of insulating from a messy, uncomfortable and unpleasant task to one we genuinely looked forward to.
Choosing a natural insulation product was a key priority for us, and Thermafleece CosyWool proved to be an excellent choice. We liked that it’s British made and supports local farmers, while also allowing our older property to breathe naturally.
CosyWool is a versatile insulation rich in British sheep’s wool and the ideal choice for all round performance and value for money. The wool rich blend ensured the full benefit of sheep’s wool with enhanced performance, durability and sustainability.
The moisture wicking properties together with the air purifying quality of CosyWool are the real reason I always choose it, allowing the building to breathe and removing toxins from the air make it the obvious choice.
fantastic to work with
This stuff is so much easier to install than rockwool, fibreglass or celotex.
Great product. Very pleasant and easy to use.
Simply excellent! Gone are the itches of fibre glass loft insulation instead a natural product of sheep’s wool, wrapped around your house for warmth. Must try a wool jumper again myself!
Great price and product
Thermafleece insulation has transformed our house. It was easy to install in our attic – we did it ourselves – it was all done in a day. Best thing ever.
No irritation from the sheep’s wool, made the room warmer straight away.
Worth it just for the abilty to breathe while using it and not getting itchy. Rips apart easily with hands or decent scissort. Excellent Product.
So easy to work with and has made a real difference to the warmth in the room below. Will be looking to replace all our loft insulation with this
Excellent quality insulation.
Effective and easy to use, fast and great service.
I’ve used the wool insulation for my campervan conversion very happy with the with the product
Great to handle and very easy to install.
Exactly as described, perfect for the job I was doing.
Excellent product, service, and delivery
Good price for item that we have used before. Straight forward order and delivery.
Really helpful with getting the right amount and overall great service, super range of products. about to buy again!
Take a look at the projects showing the versatility of our products.
We understand that choosing the right insulation for your project can be daunting. That’s why our team is on hand. We offer impartial and truthful advice as well as providing general and technical help. So feel free to submit an enquiry via our contact page.
Alternatively call us on 01768 486 285
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