We have provided a selection of our most frequently asked questions & answers. However, if you can’t find what you are looking for or would like further information then please call us on 01768 485050 or email enquiries@naturalinsulations.co.uk
General FAQs
How do I reduce noise from next door?
To reduce noise from next door can be a very complex problem to solve. Specialist acoustic consultants can help. Natural fibre insulation such as Thermafleece can be used as part of noise reducing measures in a building.
How many rolls of tape do I need to seal the joints in a roll of membrane
The general rule of thumb for tape quantities:
Roll of 1 x 75 membrane = 4 rolls of 5/6 cm tape
Roll of 1 x 25 membrane = 2 rolls of tape.
What is a Variable Surface Diffusion (VSD) Membrane
VSD Membranes are used in building construction to control the movement of water vapour from the inside of the building and through to the building fabric itself, helping to prevent condensation from forming on the inside of the building fabric which can lead to mould growth , decay and low air quality. Because VSD membranes can effectively resist air pressure, they are used to improve air tightness and minimise air leaking within the building fabric.
How do Breather Membranes work?
Installed on the cold side of the insulation -The inside face of the Breather Membrane contains pores or holes which allow water vapour and other gas molecules to pass through from inside to the outside of the building.
Because these gas molecules are incredibly small (less than 3 millionths of 1mm) the membrane can appear solid to the naked eye but will still allow large quantities of water vapour to pass through.
The outside of the membrane stops liquid water ingress (rain/snow) from the outside of the building to the inside, serving as an extra layer of protection within the roof or wall when the cladding material itself may not be watertight (e.g. tiles)
Which way round do you install Thermafleece Breather Membrane?
There are two sides to the Thermafleece Breather Membrane, a grey side with overlapping markings (dashed line) and a white side. The grey side should face outward and the white side should face inward toward the inside of the building so in a floor, the grey side faces the ground and in a roof, the grey side faces the sky.
The membrane is vapour open in both directions so if the membrane is inadvertently installed the wrong side out on a floor it doesn’t impact on the performance. The grey side has a higher UV stability which is important for roofs and walls when the membrane is exposed to light during installation but not relevant for floors.
How much insulation do i need ?
To achieve a 0.16 U-Value in a loft you need to install:
Thermafleece Cosywool to a depth of 240mm
SupaSoft to a depth of 250mm
Fibre glass to 270mm
How do I support insulation in a ceiling?
To support insulation in a ceiling or wall, the easiest thing to do is staple string to the joist and run across the underside in a zig zag pattern and back again so the insulation is supported with an X pattern.
How much loft insulation do i need?
If you are upgrading your loft, the more insulation you can install the better, but typically you should install at least 240mm of Thermafleece CosyWool or UltraWool. / a natural fibre insulation.
How long does delivery take?
Our typical lead time is 3 working days subject to availability and the majority of our product is in stock at all times.
For larger quantities lead time is 5 – 7 working days, please phone if specific dates are required for your project.
Next day or weekend delivery is available please contact us for details.
Tel: 01768 485050 or email enquiries@naturalinsulations.co.uk
What does insulation do?
Thermafleece sheep’s wool insulation is multifunctional
- Reduces Heat Loss
- Improves acoustics
- Helps balance moisture and humidity
- Reduces summertime overheating
- Improves indoor air quality
- Impacts sustainability
- Determines fire behaviour
- Influences buildability
Can I use my loft area for storage after insulating?
We would recommend installing loft legs over the joists and boarding on top of the loft leg. This ensures that you have an effective depth of insulation. Boarding directly onto joists will significantly reduce the thickness of insulation and therefore the overall performance. Find out more about loft legs
How do you maintain ventilation at the eaves?
The simplest thing to do is not to push the insulation tight against the roofing felt at the eaves level. In addition insert eaves ventilation trays to maintain the ventilation opening.
Are any of your products suitable for pitched rafters of a roof?
Yes. Thermafleece and Steico insulation are suitable in all roof applications. Please contact us for further details or download a copy of our warm roof application notes from our Help and Advice Section
Should you insulate between joists or over?
You should insulate between joists and over joists wherever possible. Run the layer over the joists cross-ways to make sure no air gaps run through the insulation from the ceiling level.
How do I reduce noise from downstairs?
A number of measures are required to reduce noise from downstairs one of which is to install an absorbent insulation between the joists. Insulation such as Thermafleece can be used as an effective absorbent material. For depths of 100mm or greater Thermafleece CosyWool can be used. For depths of less than 100mm Thermafleece UltraWool will give the best performance.
What product can I use to achieve a 1 hour fire rated floor?
We sell products rather than specific systems, all of which are fire tested. Because a 1 hour fire rated floor is a system of products, you should consult the floor system supplier.
Can you use natural fibre insulation with electrical wires and cables?
As with all insulation, electrical cables should be sufficiently rated if they are passing within insulation.
What is the lifespan of natural fibre insulations?
Natural fibre insulations that contains a binder such as Thermafleece will last the lifespan of the building.
How do natural insulations compare to other insulation materials?
Unlike man-made fibres, natural fibres are breathable meaning they can bind and release moisture and still be dry. This is a very important property when it comes to insulation because heat and moisture are very closely linked. Natural fibre insulation is better at absorbing heat which helps reduce summertime over-heating. They also provide excellent acoustic performance.
What is natural fibre insulation?
Natural fibre insulation uses the breathability and natural insulating properties of natural fibres. Therefore creating safe effective and sustainable insulation for your building. Natural fibres commonly used for insulation include, sheep’s wool, hemp and wood fibres.
Do interior walls need insulation?
You can use insulation in interior walls to prevent heat being lost into adjoining rooms. Insulating internal walls will also reduce the amount of noise moving from one room to another.
Can you add insulation to existing walls?
Yes you can add insulation to existing walls. However care must be taken to ensure that moisture doesn’t enter and become trapped within the insulation and wall. Please contact us for further advice.
Can insulation save me money?
Insulation can save you money as it prevents heat loss. Which in turn reduces the amount of energy used to heat your home. Finally reducing the amount it costs to heat your home. Insulation does many other things such as preventing your home from getting too hot in the summer and helps reduce the impact of sound. Breathable insulation such as Thermafleece can also help regulate humidity levels within the building fabric.
What is the best loft insulation material?
Certainly the best loft insulation for all round performance and true breathability; we would recommend Thermafleece British sheep’s wool insulation. However a cost effective alternative to traditional insulation (with a well ventilated roof); we would recommend SupaSoft recycled plastic bottle insulation.
What type of insulation is suitable for vegans?
SupaSoft Insulation, NatraHemp and Steico wood fibre products are suitable insulation for vegans.
SupaSoft Insulation is made from recycled plastic bottles, so SupaSoft doesn’t just save you money and cut carbon emissions but also helps reduce harmful plastic from entering the food chain.
NatraHemp is medium density insulation rich in home-grown hemp fibres. A safe, efficient and durable alternative when plant fibre is the preferred choice.
Steicoflex is a flexible insulation slab made from forest thinnings and saw mill residues. It is a high density product with good acoustic properties.
Why Should I use a Natural Insulation?
Why Natural Insulation:
- Are more thermally efficient than mineral fibre
- Use less energy and emit less CO2 in manufacture than mineral fibre (particularly Thermofloc)
- Are safer to handle than mineral fibre
- Have the ability to absorb and desorb moisture without losing their efficiency
- They can store CO2 during growth (hemp)
- Help UK farmers find a market for their sheep wool (Thermafleece)
- At the end of their (long) life compost or incinerate for energy use
- Thermofloc makes use of recycled newsprint
Do you deliver at weekends?
Next day or weekend delivery is available please contact us for details.
To speak to us about receiving your order next day or on a Saturday please phone on 01768 485050.
Delivery options exclude Bank Holidays and weekends.
Further Natural Insulations delivery process information is available on our Delivery Page. However if you require further information or have an order to place please contact the office on 01768 485050. We will be happy to help.
Can I lay natural or recycled insulation on top of existing mineral wool insulation in my loft?
You can lay all our insulations on top of existing insulation. Even Thermofloc, a loose insulation made from recycled paper.
Do I need to insulate my loft hatch?
Yes, something like 5% of heat is lost through your loft hatch, so it should be insulated.
I want to insulate a sloping roof. Are your natural and recycled insulation suitable?
Yes, all our insulations are suitable but with an existing roof you must leave a 50mm air gap between the roof tiles and the back of the insulation.
Can natural and recycled insulations be cut easily?
Roll and Cut Method: Tools Required: 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: 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.
Take a look at the video on YouTube
Or visit our health and advice page to download the How to cut thermafleece Application Notes
Alternatively, cut Thermafleece and SupaSoft insulations using a straight edge and a Stanley knife, an insulation cutting knife or simply torn apart.
For more accurate cutting, tightly compress or clamp the insulation between two pieces of solid 15mm board. Overhang where you want to cut keeping the two board edges aligned. Saw cut the edge using an insulation cutting knife or another sharp, scalloped edged knife. Keep the blade firm and square against both board edges throughout. Trim any fine remaining fibres with large scissors or shears.
Are any of your insulations suitable for cavity walls?
No, there is too much moisture in the cavity for a natural insulation.
Sheeps wool insulation FAQs
Why does Thermafleece need a synthetic binder?
To ensure that the insulation maintains its shape throughout its service life Thermafleece uses a synthetic binder. There are no natural materials available that can do this. Consequently every effort has been taken to ensure that the virgin polyester content is kept to a minimum.
How does Thermafleece react to fire?
Thermafleece will not contribute towards the developmental stages of fire. Thermafleece sheep’s wool insulation complies with British Standard BS 5803-4 for flammability and resistance to smouldering.
How does the thermal performance of Thermafleece compare to other insulation?
Thermal performance of Thermafleece CosyWool is approximately 10% more thermally efficient than low density glass fibre insulation. Thermafleece UltraWool is more than 20% efficient
What is the best acoustic insulation?
Sheep’s wool is the best acoustic insulation. Because of their irregular surface, shape and density, natural fibres such as sheep’s wool are very effective at disrupting sound. That’s one of the reasons why sheep’s wool insulation can provide acoustic performance comparable to the best mineral fibre products.
What are the environmental benefits of sheep’s wool insulation?
The environmental benefits of sheep’s wool insulation are many. At Thermafleece we use the coarse coloured wool from hardy hill sheep which would otherwise go to waste to make our thermafleece sheep’s wool insulation. All our wool is British and we manufacture in Yorkshire, the home of British Wool.
Each kg of natural fibre locks up about 2 kg of carbon dioxide which helps remove CO2 from the atmosphere. Furthermore, once installed in your property Thermafleece will last the life of the building significantly reducing the impacts of replacement and repair.
Thermafleece is breathable, allowing a healthy moisture balance which helps protect the building fabric and health. It helps your building stay warm in colder months, helping to reduce energy bills whilst the higher thermal mass buffers the heat to reduce overheating in summertime. It is very effective at lowering sound levels within the building and is itch free, safe and easy to install.
For further information contact us on 01768 485050 or email enquiries@naturalinsulations.co.uk
What is the density of Thermafleece?
The density of Thermafleece varies from 18kg/m3 to 32kg/m3 depending on the product. To clarify refer to product fact sheets for details – available to download from our product information pages.
Can I use thermafleece insulation in cavity walls?
Thermafleece insulation can’t be used as insulation in cavity walls of brick and block or block and block. It can be used within timber frame walls or within a frame on the inside of a solid wall.
Do I need protective clothing to install sheep’s wool insulation?
All the insulation we supply is completely safe to handle. However, because lofts are inherently dusty places, we would always recommend using protective equipment when working in a loft.
How is thermafleece sheep’s wool insulation made?
Do you want to know how thermafleece sheep’s wool insulation is made? Take a look at The Campaign for Wool video. It will show you the thermafleece production process from start to finish.
Is Thermafleece made from British Wool?
Yes, Thermafleece is made from British Wool.
All the wool used in our Thermafleece sheep’s wool insulation comes from British flocks, roughly split between England, Scotland and Wales. British flocks are relatively small in size compared to larger wool producing nations like Australia. The sheep we use for Thermafleece run free on the mountains and fells and are brought down to lower lying land in the winter. They are not housed indoors although in lambing season the ewes may be brought under cover to protect them.
All the wool clip comes from live sheep that are shorn in the spring of each year. All our wool is purchased through British Wool which is the government agency that manages the supply of all British wool bought and sold within the UK. They also conduct training and promote welfare. Our wool is only purchased at the British Wool auctions by a licenced wool merchant.
We are a British Wool licensee. Both British Wool and our company take animal welfare very seriously. You can find information on animal welfare on the British Wool web site:
I am using Thermafleece in my van conversion – do i need a Vapour barrier?
You would definitely need a vapour control layer in this application. The outer metal skin of the van will produce a heavy condensation point without a control layer and possible deterioration of the insulation could take place.
How do I install Thermafleece in a suspended floor?
Thermafleece is an ideal choice for helping minimise heat loss through suspended floors. Fit the insulation between the joists ensuring all joints are close-butted to avoid air gaps. Overlap additional layers to reduce thermal bridging and air gaps. Pay particular attention to the perimeter of the floor, filling every gap with insulation.
Support insulation with netting 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. Breather membranes are windproof so reducing the chill factor, are dustproof so keeping the insulation clean, and permeable so the system can still breathe and the timbers have access to moisture to maintain moisture content levels.
If the flooring comprises open floorboards, you could install an airtight breather membrane on the top side of the Thermafleece to avoid a build-up of dust and debris on top of the insulation and to reduce any movement.
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.
Our Help and Advice section has Application Notes with diagrams available to download
How long does it take for Thermafleece CosyWool Roll to regain once unpackaged?
Thermafleece CosyWool Roll is delivered compress packed – this allows us to increase the number of packs we can get on a pallet and therefore minimise transport costs.
Once your CosyWool Roll is unpacked it will regain to its full depth within 5-7 days . It will continue to regain whilst in situ.
How do I cut Thermafleece sheeps wool insulation?
How to Cut Thermafleece: Although tearing thermafleece to fit is self-explanatory, cutting Thermafleece accurately is always a good topic for a discussion.
Roll and Cut Method: Tools Required: 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: 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.
Take a look at the video on YouTube
Or visit our health and advice page to download the How to cut thermafleece Application Notes
Compressing between boards: 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.
Can I insulate my home using Thermafleece with the Green Homes Grant?
If you want information about the Green Homes Grant Scheme, then take a look at the Simple Energy Advice Service https://www.simpleenergyadvice.org.uk/pages/green-homes-grant . You will need to find a Trust Mark approved trades person to do the work, then advise the Trust Mark Approved trades person to contact us.
Recycled insulation FAQs
Is recycled plastic insulation suitable for campervan conversions?
Yes, SupaSoft is an insulation suitable for campervan conversions. Place between the campervan panels or simply lay on top of existing van insulation to improve overall insulation performance. SupaSoft insulation is an open non-woven material that allows water vapour to pass through the insulation and does not support mould growth.
How many plastic bottles does it take to insulate a loft?
It takes an average of 10,000 waste plastic bottles to produce enough SupaSoft to insulate a typical loft. That’s 10,000 plastic bottles that would otherwise have been buried in landfill, incinerated or left to litter the environment.
‘Let’s stop using things once and start dealing with the legacy we have created. SupaSoft Insulation provides a long term use for waste plastics that helps reduce home energy at the same time’ – Eden Renewable Innovations Ltd
Why use recycled plastic insulation?
SupaSoft is a sustainable, recycled plastic bottle insulation that is good for your home, your family, and the environment. Perfect for lofts, SupaSoft offers a long term solution to deal with the legacy of waste plastic, most of which comes from single-use applications.
SupaSoft Insulation is a low energy alternative to Rockwool and fibreglass. Totally safe to handle and it can be installed by the DIY home-owner or a professional. Moreover it will not need to be replaced and lasts the lifetime of the building.
All our SupaSoft Recycled Plastic Insulation is manufactured locally in the UK, supporting local enterprise. In addition helping to reduce the carbon emissions that arise when transporting bulky materials long distances.
How long does SupaSoft Insulation last?
SupaSoft is made from recycled PET (polyester) and is extremely durable. Because the binder is made from PET it does not degrade or slump over time. This means that SupaSoft will last the life of the building so once installed there is no need to replace.
Is there a cost effective alternative to fibreglass?
Insulating with SupaSoft recycled plastic bottle insulation is a very cost effective alternative to fibreglass or other mineral insulation. In addition the energy it saves means SupaSoft insulation quickly pays for itself.
I already have some insulation in my loft but it is not very thick, will this have to be removed or can it be topped up?
You can lay SupaSoft on top of existing insulation although the amount of additional insulation will depend on how much existing insulation is in place and what condition it is in. For instance, if the insulation is in very poor condition we would recommend adding 250mm of SupaSoft on top. However if the existing insulation is in very good condition, add sufficient SupaSoft to achieve a total insulation thickness of 270mm. Check under and around existing insulation for any signs of damp or water damage.
What is the recommended thickness for loft insulation?
The recommended thickness for loft insulation for an existing building is 250mm of SupaSoft. For added performance in an existing building or for a new build use 300mm.
For further information download our Insulating your loft with SupaSoft Insulation factsheet
What is Thermofloc recycled insulation made of?
Thermofloc is a loose fill cellulose insulation made from recycled newspaper combined with a mineral fire retardant. A sustainable and cost effective way to insulate horizontal surfaces such as your loft or floors.
What U-value can be achieved with a THERMOFLOC insulated construction?
The U-value achieved will depend on the thickness of Thermofloc. However a thermal conductivity of 0.039 W/mK ensures a consistent high performance envelope of Thermofloc insulation helping minimise heat loss in the winter and keeping your building comfortably cool in the summer.
Install Thermofloc at a density that provides additional thermal mass to the building envelope. Therefore helping smooth out highs and lows as the building fabric warms and cools.
Please contact us on 01768 485050 for specific U-Value Calculations
Can SupaSoft be used as wall insulation as well as loft?
Yes you can use Supasoft in a stud application. The wall must be in good, dry condition, no damp. There would also have to be a vapour control layer between the internal finish and the insulation to limit moisture migration.
Can SupaSoft Insulation be used in a stud wall application?
Yes, SupaSoft recycled plastic bottle insulation can be used in a wall application. The wall must be good, dry conditions and with no damp. There would also have to be a vapour control layer between the internal finish and the insulation to limit moisture migration.
Is SupaSoft Recycled Plastic Bottle insulation suitable for suspended floors?
Supasoft is an ideal product for use in a suspended floor application. It is a permeable product and it has no intrinsic food value for moth or beetle. There will also be a good acoustic result.
How do I attach SupaSoft insulation to the inside of my van conversion?
Attach the insulation to the inside of the van using either strong double sided carpet tape or contact carpet adhesive.
How many recycled plastic bottles are kept out of landfill by using SupaSoft Insualtion?
There are approximately 800 recycled plastic bottles in every pack of SupaSoft, so that equates to 136.7 per m2
Hemp and wood fibre insulation FAQs
What is Hemp insulation?
Hemp is a fast-growing, low-impact plant crop that produces fine fibres suitable for insulation. Thermafleece NatraHemp is a medium density insulation rich in home-grown hemp fibres and is a safe, efficient and durable alternative when plant fibre is the preferred choice.
Is Hemp a good insulator?
Hemp is a good insulator. Thermafleece NatraHemp fits securely between rafters, joists and studs providing excellent thermal insulation performance. What’s more, with a density of 25 kg/m3, Thermafleece NatraHemp can provide good acoustic insulation in a variety of systems.
Is Hemp insulation itchy?
Thermafleece Natra Hemp insulation is harmless when installed without gloves or protective clothing. Although we recommend to wear a dust mask in enclosed spaces such as lofts. Thermafleece NatraHemp is not irritating to the skin, eyes or respiratory tract.
How do I cut Hemp Insulation?
How to cut hemp insulation guide. Cut Thermafleece NatraHemp using a straight edge and a Stanley knife, or simply tear it 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.
Is Hemp insulation suitable for vegans?
NatraHemp is hemp insulation suitable for vegans. A medium density insulation rich in home-grown hemp fibres and suitable for vegan use. NatraHemp is a safe, efficient and durable alternative when plant fibre is the preferred choice.
What is Steicoflex insulation made from?
Steicoflex is a wood based, highly versatile and eco-friendly insulation slab. Made from wood fibres, poly-olefin fibre (a high quality binding fibre found in nappies), and ammonium phosphate (for fire protection). It is a high density product with good acoustic properties.
Where can I use Steicoflex insulation?
Use Steicoflex between rafters and joists as a dry wall insulation and as loft insulation. Also use it to insulate timber frame structures, walls and internal partitions.