The Benefits of Natural Insulation

Insulation, Membranes & Felts
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The Benefits of Natural Insulation

Installing insulation is one of the best ways to improve the energy efficiency of your home. Not only will it keep you warm in the winter and cool in the summer, but you’ll see a marked reduction in energy bills too. Awareness of the impact we have on the environment with every decision we make is growing, and that includes the carbon emissions from our homes. The British Government has launched an initiative to reach zero net carbon emissions by 2050, and improving the insulation in British homes is one of the best ways to help. 

There is an increasingly popular school of thought known as Passive Housing. This involves making living spaces as energy-efficient as possible, leading to a reduction in required heating of up to 90%. We can all take inspiration from the Passive House concept by insulating our homes effectively. Not only will you be helping the environment, but you’ll be saving plenty of money too. According to The Renewable Energy Hub, the installation of loft insulation alone can save up to £150 per year, paying for itself within two years. 

In line with our growing environmental consciousness, many homeowners and property developers are looking for alternatives to manmade insulation. Natural insulation such as Sheep’s wool insulation is not only far more environmentally friendly, but carries a host of other benefits. As well as boasting similar thermal and acoustic efficiency, natural insulation materials are also better for your health. This isn’t just during installation but also throughout the lifespan of the insulation in your home. 

The best homes are more than just living spaces. They enhance the physical and mental wellbeing of everyone dwelling within them. Utilising natural insulation in your home is one way to achieve this, thanks to greater levels of comfort, cleaner internal air quality, and more. If you’re looking to make your home more energy-efficient and kinder to the world around us, natural insulation is the perfect eco-friendly solution for you. 

What Are The Different Types of Natural Insulation? 

There are many benefits that all-natural insulation materials share. These include the fact that they have low levels of embodied carbon, they’re non-toxic, healthy, recyclable, and more. In addition to these, there are numerous unique advantages to each material. Some are more flexible than others, meaning they fit into unusually-shaped spaces. Others come in more rigid forms such as slabs, making them perfect for insulating vertical surfaces. 

Sheep's Wool Insulation  

As you may have guessed, these rolls and slabs are made from sheep’s wool, often along with a percentage of recycled plastic. Sheep’s wool insulation is an incredibly popular choice for use in eco builds or in older properties. Its popularity is growing across all build types however thanks to its efficiency, healthiness, and sustainability.  

This wool insulation from manufacturers such as Thermafleece traps air in millions of pockets in the crimps between the fibres. This makes it an incredibly effective thermal and acoustic insulator. As well as energy-efficiency, sheep’s wool also combats humidity in the air very effectively. Sheep’s wool is hygroscopic; meaning it absorbs excess moisture from the air. This helps to prevent condensation, damp, and mould – all common hazards found in roof spaces. What’s more, sheep wool insulation can absorb up to 30% of its weight without losing any effectiveness! 

Installing sheep’s wool insulation will also make your home a healthier place to live. This is because the wool improves internal air quality by absorbing airborne pollutants such as formaldehyde, nitrous dioxide and sulphur dioxide. Having wool insulation inside your home is also a way to make it safer from fires, as wool tends to char rather than flame. 

Recycled Plastic Insulation 

Most often made from recycled polyethelene terephthalate (or PET, for short!) from plastic bottles, this is another excellent sustainable form of natural insulation. This form of insulation is also becoming increasingly popular, as it has the bonus of removing a tremendous amount of plastic from waste streams. For example, it takes around 10,000 recycled plastic bottles to manufacture enough Thermafleece SupaSoft to insulate a loft, which would have otherwise found themselves in a landfill. 

In the same way that we’re all familiar with the cosiness of a woolly jumper from a sheep, Thermafleece has found a new innovative way to take existing technology and find a use for it as insulation. We all know how cosy duvets and pillows made from polyester fibres are, and now we have the chance to use them to keep our homes warm too. Installing recycled plastic insulation into your roof space is an excellent way to make it more comfortable and reduce energy bills. 

As well as boasting top-notch performance and being kinder to the environment, recycled plastic insulation is kind to humans too. It contains no harmful chemicals, making it safe to handle and install, requiring no PPE. It’s also much healthier for the inhabitants throughout its long lifespan. Recycled plastic insulation is an excellent way to reduce pressure on already strained waste streams, and because it will last the lifetime of the building, it’s a wise long-term investment financially as well as ecologically. 

Hemp Insulation  

Hemp is an incredibly diverse material, able to be used for a wide variety of applications. It has been used throughout history to create ropes, sails, clothing, paper, and more. Hemp has been known to grow in the harshest of conditions and absorbs huge amounts of CO2 from the atmosphere. According to Science Direct, hemp fibres can lock in up to 2 tonnes of CO2 per tonne of fibres

Today, it’s also an excellent choice of eco-friendly insulation, as it combines outstanding performance with a low carbon footprint and sustainability. Hemp insulation is brilliantly durable, able to withstand sagging and compression that plagues other forms of insulation, without sacrificing performance. As well as this, hemp is highly breathable, preventing the build-up of mildew, mould or fungi. 

Hemp insulation provides excellent thermal and acoustic performance. It’s also malleable, making it easy to achieve a snug fit between rafters, joists, and studs for an airtight seal. Like sheep’s wool, hemp is also fire-resistant, making it a safer choice for your home. 

Wood Fibre Insulation  

Wood fibre insulation is made from recycled coniferous wood. Waste wood is collected from sawmills and other sites and then pressurised under extreme heat to create the wood fibres. This natural form of insulation boasts outstanding performance against thermal and acoustic bridging. This is thanks to its high mass and the porous structure of the wood. This means your home will be a peaceful, comfortable place to live – with lower energy bills!  

Wood fibre insulation is also safe in the event of a fire. This is because the outer layer of the insulation board carbonises, preventing oxygen from penetrating any further, weakening the blaze. It’s also highly breathable, regulating moisture levels in the air to prevent humidity and condensation. As this insulation is made from waste wood fibres, it’s highly sustainable, and can even be recycled again at the end of its life! 

Cork Insulation  

Made from the bark of the cork oak tree, cork insulation is another natural insulation material that has become more popular in recent years. Cork insulation is incredibly lightweight and damp-proof, which means it is excellent at resisting rot and mould. Available in the form of both insulation boards and granules, it can be used for a wide variety of applications. Cork insulation boards are excellent for loft insulation, as well as walls and floors. The granules, however, are better-suited to insulating cavity walls and beneath screed.  

Cork insulation is incredibly safe, rated Euroclass B2 for fire safety, making it extremely fireproof. In addition to fire resistance, it is also resistant to infestation from termites, mice, rats or other pests that can plague insulation, particularly in disused loft spaces. As it is a healthy, natural material, installing cork insulation causes no irritation and therefore requires no PPE. 

Cellulose Wadding Insulation 

Cellulose wadding is an incredibly safe and effective form of natural insulation. It’s made from recycled paper, which is chemically treated to be fire safe. Cellulose wadding insulation can be bought either as boards or loose – which is ideal for filling cavity walls. Despite being inexpensive, cellulose wadding has similar thermal efficiency to glass mineral wool, the most widespread synthetic form of insulation. Cellulose wadding is safe and easy to install and boasts great thermal and acoustic performance.  

Coconut Fibre Insulation  

Coconut fibre insulation, also known as coconut wool insulation, is another form of natural insulation. It is made from the woolly fibres on the outside of coconuts, with surprising levels of effectiveness, particularly as acoustic insulation. Coconut fibre insulation can be found as flexible insulation rolls, semi-rigid insulation boards or in a loose form. Coconut wool is also very vapour permeable, fighting humidity in the air. It’s safe to install and recyclable at the end of its lifespan. 

Is Natural Insulation Right for My Home? 

Natural insulation materials can be used in virtually any kind of building, whether it’s a residential property, office space or factory. Natural insulation lends itself particularly well to older properties, including even listed buildings. This is primarily thanks to its exceptional breathability and vapour permeability. This allows the natural insulation material to fight excess moisture in the air, which can be particularly damaging to historic timber structures. Natural insulation materials are also completely safe to work with, making it easy to cut and shape into the unusual dimensions one may find in the roof and loft spaces of older properties. As well as protecting the integrity of historic construction, natural insulation is the ideal solution for anyone looking to create a healthier, greener home. For more information about the benefits of natural insulation for older properties, The Society for the Protection on Ancient Buildings provides further guidance here

What Are the Benefits of Natural Insulation?  


As they contain no harsh chemicals or irritating fibres, natural insulation materials are not generally harmful to health. But the health benefits of natural insulation are greater than the safe materials. The added breathability and ventilation also play a key role. Synthetic forms of insulation such as polyisocyanurate or PIR insulation are non-sorptive, which means they cannot manage moisture in the air effectively. This then requires additional ventilation in the home, particularly in the roof space to combat condensation and excess moisture build-up. As well as being more likely environments for mould and mildew to develop, the internal air quality is lower, and less healthy.  

In contrast to this, there is a growing body of evidence that relying purely on additional ventilation from gable vents, ridge vents and so on is insufficient. According to a study by the Alliance for Sustainable Building Products, without adequate materials such as natural insulation within the home in addition to ventilation, significant health risks are present not only to occupants but also the structural integrity of the building.  

This means that for us to build healthier, more sustainable and more comfortable homes, the use of natural materials must become a priority. Thankfully, there are already many natural insulation products available today which allow homeowners and property developers to move towards this goal.   

Cleaner Air 

Using natural insulation in your home isn’t just helping the earth, it’s cleaning the air inside your property too. Natural insulation materials such as sheep’s wool emit zero toxins throughout their long lifespan and even act to absorb harmful substances from the air too. This is because sheep’s wool is a natural protein, made up of 18 amino acid chains. These proteins react and allow the wool insulation to draw harmful substances such as formaldehyde from the air. These substances are then neutralised through a process known as Chemisorption

Indoor Air Pollution 

According to a study by the Royal College of Physicians, titled ‘Every Breath We Take’, there is a little-known yet serious problem of indoor air pollution. Air pollution is a problem that must be addressed, as it leads to nearly ten thousand premature deaths every year in London alone. Most people think of cars, planes and other vehicles when we think of air pollution, but indoor air pollution is an as yet unrecognised danger. The authors conclude that the use of harmless, natural materials in construction such as eco-friendly insulation would be a very effective measure at reducing VOC and particulate levels, thereby reducing the damage to health.  

Preventing Overheating in Summer  

According to the British Lung Foundation, excessive heat can exacerbate existing respiratory and cardiovascular health conditions. In addition, studies undertaken by Arup and CIBSE have found that internal temperatures above 35C present significant danger of heat stress, particularly among older or vulnerable populations. Insulating buildings with fabrics that have a low thermal mass makes them more susceptible to overheating, especially in the summer. Thankfully, natural insulation materials tend to have very high thermal mass and improve ventilation, making them ideal for avoiding this potentially dangerous scenario. 


Effective insulation in your home helps to make it a more comfortable living space by moderating the temperature and dampening sound. Natural insulation is very effective at combatting excess heat, cold and noise pollution. This is in part due to its increased mass, which makes it more efficient than manmade insulation solutions. 

Thermal Performance 

Its effectiveness at keeping our home warm in the winter and cool in the summer is the first factor we think of when considering the performance of insulation. As well as being more comfortable to live in, this comes with multiple other benefits. Keeping the loft space cool and well-ventilated using natural insulation helps to preserve the timber in roof trusses, which are vital in supporting the roof. The cool air also deters warmth-loving pests such as insects and rodents. With adequate natural loft installation, we can prevent excess heat from escaping from the home into the loft space. 

Natural insulation materials such as sheep’s wool often boast fantastic thermal performance. This is due to the millions of air pockets formed between the crimped woolen fibres which trap air and act as a thermal barrier. Natural insulation can even outdo manmade solutions, with many of the most energy-efficient properties in the world employing natural insulation.  

Another factor that makes natural insulation even better at preserving a stable temperature in the home is the presence of water. Natural insulation materials tend to contain water that is bound to their fibres. Water has a naturally very high heat capacity, twice that of concrete – boosting its ability to absorb heat. In addition, natural insulation materials also tend to have much higher thermal mass.  

Another benefit of installing eco-friendly thermal insulation is the much more even distribution of heat throughout your home. When surfaces such as internal walls are at a more stable temperature, they emit more radiant heat, which is considered more pleasant than convection. This means it’s possible to keep a room at a lower ambient temperature without affecting comfort levels. In fact, a 1C reduction in temperature can lead to a 5% saving on energy costs. 

Acoustic Performance 

Due to the high density and flexibility of natural insulation fibres, they often outperform manmade solutions as acoustic insulation. A higher density material such as sheep’s wool or wood fibre insulation is much more effective at dampening noise reverberations. This means that the sounds of a busy street will be much less intrusive, making your home a more restful place to live.  

Another factor that aids the acoustic performance of natural insulation is its irregularity compared to synthetic materials. As the fibres are naturally-occurring, they are slightly irregular, which makes them even better at disrupting soundwaves. 


Their sustainability and minimal impact on the environment are two of the greatest advantages of natural insulation. This is particularly pertinent as all elements of our society are moving towards sustainable solutions. Compared to manmade insulation, natural materials cause almost no damage to the environment, either in their production or disposal. In fact, many natural insulation materials don’t just reduce a building’s carbon footprint – they even sequester CO2 emissions throughout their lifetime! 

Reduced Carbon Emissions 

Natural insulation materials have a much smaller carbon footprint when compared to traditional synthetic solutions such as PIR insulation or glass mineral wool. This is true both during production and their lifespan. 

Products such as Thermafleece CosyWool offer homeowners a greener alternative. For example, during the production of CosyWool Sheep’s Wool Insulation Rolls absolutely no emissions are created. This is because no burning is required during manufacture. The hardy wool from British sheep is combined with recycled polyester, then stretched and compressed. This compressed state allows tighter packing during transportation – further reducing carbon emissions. 

The production of recycled plastic insulation requires a great amount of heat as the bottles are melted down. The impact on the environment is offset however by the fact that many tonnes of waste plastic is being reused and not going to landfill. 

The hemp insulation production process also has a minimal impact on the environment. Hemp plants are incredibly tough, growing in tough conditions and requiring little water, with no need for artificial irrigation. Hemp naturally deters the growth of weeds, meaning pesticides aren’t needed to protect the plant. Hemp is also grown as a “break crop” between rotations, allowing the soil to regain its natural nutrient levels required for other crops later. Hemp is even carbon negative, as it absorbs up to double its weight in CO2, which is never released into the atmosphere, even after harvesting.  

Natural Insulation is Recyclable 

If you’re concerned with your home’s effect on the environment, it’s also important to consider what will happen at the end of the building materials’ lifecycle. Thankfully, natural insulation materials are 100% recyclable and not harmful to the environment, requiring no specialist waste streams.  


One thing you must consider when choosing insulation is longevity. This extends not only to the lifespan and performance over time of the insulation itself, but also the effect it may have on the longevity of your home. For example, many synthetic insulation materials like glass mineral wool can sag or become compressed over time, which affects their performance. Natural materials such as sheep’s wool or hemp insulation keep their shape much more reliably, and can even be expected to last longer than your home!   

Another great risk to building longevity is damage caused by excess moisture. Condensation build-up can lead to issues such as water ingress, mould, damp, rot, mildew and more – all of which cause structural damage and require costly repairs. Natural insulation materials tend to be superb at drawing excess moisture from the air and act as a much greater buffer, shoring up a building’s durability. 

Breathability and Vapour Permeability 

Insulation made from natural fibres is the most effective solution for breathability and vapour permeation. This is because the fibres regulate humidity levels and excess moisture in their air by binding and releasing moisture as needed. This is important for the longevity and comfort of a home as excess moisture can lead to problems such as damp and mould. 

This brilliant ability to regulate moisture makes natural insulation materials perfect for timber-framed homes such as period properties. As wood is highly susceptible to damage due to water, it’s vital to keep your home’s structural integrity intact. Sheep’s wool, for example, is one of the most effective forms of natural insulation at keeping excess moisture at bay. It can absorb up to 30% of its weight in water without sacrificing performance. Plus, when the woollen fibres absorb moisture, they generate additional heat – which helps to further prevent condensation build-up.  

In a report titled ‘Health and Moisture in Buildings,’ from the UK CMB, it was concluded that: “these risks [moisture in buildings] combine with the other more clearly defined risks to the durability and value of the building fabric. It is relatively easy to see and to cost the damage done to buildings where moisture imbalance occurs. It is estimated that perhaps 70 to 80% of all building damage is due to excessive or trapped moisture” As such a preponderance of issues faced by structures are caused by water, it’s imperative that breathability is considered in all construction. In addition to preserving structural integrity, this also helps to prevent risks to human health. This is particularly important for those with respiratory issues such as asthma or COPD. 

Rodent Resistance 

Natural insulation materials are highly resistant to infestation from pests such as rodents, insects and more. These can cause damage to insulation, particularly in loft spaces and cavity walls which will require time and money to replace. 


Natural insulation materials are completely safe and generally pose no risk to human health. This is in stark contrast to something like asbestos, which was commonly used as insulation in homes across the world in the late nineteenth early twentieth century. Although we are now well-aware of the dangers it poses to health, originally it was seen as a wonder product.  

Fire Proof 

Natural insulation materials are often highly fire-proof. One of the best things about sheep’s wool is the fact that it is incredibly hard to burn. The high nitrogen content in wool allows it to resist flaming and self-extinguish. Rather than bursting into flames, sheep’s wool will char, smoulder and singe. 

As well as preventing the spread of fire itself, natural insulation materials are safer due to the fact that they contain no toxic materials. In contrast to this, when PIR insulation is burned, it will give off fumes that are toxic and very harmful to humans.  

Installing Natural Insulation  

One of the main obstacles faced by homeowners that want to replace their insulation is installing it. This can be due to the process of fitting it, or the fact that working with many manmade insulation materials is hazardous and requires the careful use of plenty of PPE.   

Natural fabrics such as sheep’s wool are completely harmless to human health. This is because they are not treated with harsh chemicals, nor do they contain any synthetic binding agents. This means a homeowner can install sheep’s wool insulation themselves without needing gloves, goggles or face masks. As many of our customers would prefer to insulate their own lofts rather than hire a tradesperson, this is a significant advantage. 

More Information 

Hopefully, this article has given you an idea of the kind of insulation that you would like to use and you can find all three types of insulation available on Roofing Megastore. And, if you need any further information about any of the products you can ask our friendly customer services team who can be reached on 01295 565565 or via the live chat on the website.  

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Please note: The information in this article has been written for information purposes only and we, therefore, take no responsibility for any purchasing decisions you make as a result of reading this article. Whilst we act as a retailer, we are not experts and we, therefore, recommend that you also refer to your manufacturer's guide and, if appropriate, consult a qualified professional before you make any final decisions.  

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