Chimney Sheep

Draught-proofing is the process of blocking up unwanted gaps in a building that let cold air in and warm air out. Keeping the warm air in will ensure that heating systems can work more efficiently, saving money on heating costs and making a building feel warmer and more comfortable. Draught-proofing doesn’t stop ventilation. Most buildings have controlled ventilation which helps to stop condensation and damp. Draughts are caused by gaps that are letting air in uncontrollably, like the small gaps under your doors or through gaps in your windows, making your home feel colder and wasting warm air.

You can read more about draught proofing on the Energy Savings Trust website.

There are lots of ways you can draught proof your house. If you have an open chimney, this is likely to be the single biggest source of air loss in your home so we would always suggest to start by using a chimney draught excluder to draught proof your chimney. Draught proofing your chimney will also decrease the effect of any other draughts coming into your home as it will stop a phenomenon called the ‘stack effect’.

You can then use a Smoke Pencil to detect where any other draughts in your home might be coming from and use the correct draught-proofing equipment to solve the problem! You can read more about different methods of draught proofing here or on the Simple Energy Advice website.

By draught proofing your chimney with a chimney draught excluder like a Chimney Sheep®!

Draught proofing your chimney can really help with the wind noise and cold draught coming from your chimney. Something like a Chimney Sheep® chimney draught excluder would be beneficial!

A Chimney Sheep® is a chimney draught excluder that stops warm air escaping from a property with an open chimney and prevents cold air coming in, making a home feel more comfortable.  It is removable and made from highly durable, naturally breathable Herdwick wool and a plastic handle (that can eventually be reused or recycled). The wool is felted to create a flexible yet sturdy material that is perfect to plug the gap just above a fireplace whilst the handle ensures easy insertion and removal. You can read more about how it works here.

It really does! We are the only chimney draught excluder to have a BBA Agrément Certificate. To achieve this the Chimney Sheep® had to go through numerous laboratory tests, on-site evaluations, quality management checks and product inspections, over several years, passing all the assessments to gain the award. The BBA is a worldwide credible industry body and the certificate means that Chimney Sheep® are recognised by building control, government departments, specifiers, and insurers as meeting the BBA’s standards of quality, safety and reliability. It provides you and them with reassurance of the product’s fitness for purpose.

A chimney balloon is a good option for some circumstances. In fact, The Chimney Balloon Co is actually our sister company, so we like them a lot! They are great if you have a fireplace you don’t use because once in place they are a bit fiddly to take in and out. The Chimney Sheep® is easy to put in and take out as many times as you like so better suited to a fireplace that is being used regularly. We would also recommend a Chimney Balloon if you have a traditional Victorian fireplace surround with a damper flap as they are much easier to get into the chimney flue than a Chimney Sheep® would be.

If you do go for an inflatable chimney balloon we would always say to avoid going for a universal sized balloon because they will not fit all sized chimneys and therefore won’t be as effective! We’d also suggest going for one from The Chimney Balloon Co as it is the only chimney balloon on the market that isn’t made if PVC. If you were to accidentally light a fire with a PVC balloon in place, it would give off chlorine gas fumes which can be quite dangerous.

The Stack effect is the movement of air into and out of buildings due to air dynamics. Chimneys are designed to draw air out of a building regardless of whether it is an active fireplace or not. The Buildings Research Establishment (BRE) states that an average of 80 cubic metres of air travel up an open chimney per hour!

The volume of air that escapes up the chimney needs to be replaced, so cold air is pulled in from other leaky parts of the building, such as keyholes, gaps around your doors and tiny gaps around your windows. Although these gaps are relatively small compared to your chimney (so small you might not be able to really see them), all these routes in for cold air can add up to make your home feel rather chilly!

You can read more about it and how it effects your home on our ‘What is a Chimney Sheep®’ page.

An open chimney is often the biggest source of heat loss in a house, similar to leaving a giant window open all the time. The Buildings Research Establishment (BRE) states that an average of 80 cubic metres of air travel up an open chimney per hour which is rather a lot! The University of Liverpool has calculated that to be around 5% of our household heat lost through an open chimney.

Yes, a Chimney Sheep® will reduce wind noise from coming down the chimney. We can’t guarantee that it will deaden all sound but having a thick layer of felt in there will definitely muffle it. It will also reduce the airflow whistling through the chimney so it will reduce noise that way. Some customers increase the amount of sound insulation by having a net bag full of insulation wool above the Chimney Sheep® to make it even more effective. In this case, we would suggest using some of our SheepWool Insulation or a large bag of our shillies, as they are both moth proof. Chimneys and how sound is amplified in them is a complicated thing but you can read a bit more about it here.

A Chimney Sheep® goes in near the bottom of the chimney, and birds like jackdaws nest at the top, though the nesting debris often finds its way to the bottom. You need a cowl that is wired into place in such a way that determined beaks can’t un-pick it.

If you have had birds nesting and have left your ‘Sheep in all summer then be very careful about removing it, it could have a range of debris collected on it from the nest.

A Chimney Sheep® stops about 5% of your household heat from escaping. The average annual UK heating bill is about £1,971 (according to Ofgem) so it would reduce that by about £99 per year on average. You can estimate how much your home might save in energy costs by using our savings calculator.

It depends on what sized Chimney Sheep® you need and how much your heating bills are per year, but on average the payback is about 6 months. To compare, double glazing windows takes about 50-60 years to pay back on average.

The felt head of a Chimney Sheep® usually lasts about 10 years and is 100% wool which means it is completely biodegradable and compostable. The handles are made with recyclable plastic therefore are extremely durable and designed to last for decades. We have designed them so that when the felt head does wear out, you can just replace it with a new felt head and keep the same handle to reduce waste and the use of excess plastic. When the time comes and you have to say goodbye to your felt head, get in touch with us.

A Chimney Sheep® will save on average about 250kg of CO2 per year. To put that into context, that is about the same amount of CO2 released if you were to drive from London to Barcelona in a petrol car.

Yes, it is. Wool is naturally fire retardant and the handles are made of fire-retardant plastic. It has been tested by High Street Textile Testing Services Ltd.

They found that the Chimney Sheep® performed well and demonstrated a good level of resistance to flaming ignition sources “such that in the event that the chimney sheep was accidentally left in situ in a chimney breast and a fire lit beneath it, the chimney sheep would not represent a significant fire hazard”.

Download the full report here.

No, it does not. Chimney Sheep® are made from Herdwick wool which is naturally breathable and will allow moisture to permeate through. A Chimney Sheep® will stop 93% of the air getting through. That extra 7% is enough to allow for sufficient ventilation.

The wool is naturally breathable and will allow moisture to permeate through. If you have a problem with damp in a chimney it may be that the warm damp air is rising into the flue then condensing on the cold walls higher up. The Chimney Sheep® will prevent this warm air from rising so should cut off this source of damp. If you have a very damp home then you should look at whether it’s properly ventilated, but usually chimneys are a source of uncontrolled ventilation and consequently provide a bit too much of it. Damp in the home is a common problem with a complicated combination of causes and solutions. Drying your laundry outside is a good way of reducing damp in the home – use a Laundry Mac to protect laundry from rain showers so you can hang it out in all weather.

The damper mechanically closes the chimney or can be partially closed to restrict the movement of air within the chimney. It will help to reduce draughts, but you will find that a lot of central heating air will still get up the chimney past the damper. We don’t want to sell you something you don’t need, but even with a damper you will benefit from having a Chimney Sheep® in place.

Even with the chimney capped a lot of warm air will rise into the chimney where it’s not needed. We don’t want to sell you something you don’t need, but the ‘Sheep has been trialled in capped chimneys with favourable results as it reduces the whistling wind noise that sometimes occurs through the chimney cap vents. It also stops dirt and mortar from spilling into the room from older chimneys.

Your woodburning stove should be properly insulated and should not require a draught excluder. If the rope around the door doesn’t fit properly then you may get draughts, which can be remedied by replacing the rope.

Gas Safe state that gas flues must not be blocked. Customers do purchase Chimney Sheep® to insulate their chimneys above gas fires that are rarely used, making sure that the gas supply is turned off,  the tag is visible and the safety sheep card is on display. However, Chimney Sheep Ltd cannot recommend that you use a Chimney Sheep® in a gas flue.

Electric fires radiate heat out into the room. A Chimney Sheep® sits above it in the chimney. Make sure it’s high enough above the fire that it’s not at any risk of getting scorched, but it should be fine.

If you have an open chimney then yes, as chimneys have been designed to constantly draw air out of a property regardless of whether a fireplace is active or not.

If you have a fireplace that you use regularly, you can still have a Chimney Sheep® as it is super simple to remove and insert as needed, using the handle attached. Before you have a fire, take it out and once your fire has finished and the chimney is cold, you can put it back in.

No. The wool is treated with “ionic protect”, a very clever treatment that changes the ionic charge of the wool fibre so the moth doesn’t even recognise it as wool. She doesn’t even try to lay her eggs on it. It’s chemical free, permanent, completely benign, and ingenious.

In the past we treated our wool with Borax. This is actually a fire retardant treatment that coats the fibre with small crystals that cause the moth larvae to perish if they eat it. It means that the larvae have to eat a small amount of the wool in order to perish, and over a long period of time this can lead to larger amounts of the product being eaten. We were not content with this as an option so have invested a lot of resources into finding a more efficient moth solution. We are lucky enough to be working with Isolenawolle in Austria who have a unique patented method of treating the wool with what they call Ionic Protect. This changes the ionic charge of the wool fibres and means the moths no longer recognise it as wool. It’s chemical-free, it’s permanent and it’s very effective – we’re delighted to have the opportunity to use it. All products sold from January 2019 onwards will have been treated with Ionic Protect.

Chimneys can be a “way in” for moths, especially if birds nest at the top, as moth larvae can occur in birds’ nests and either fall down as larvae or find their way down as newly hatched moths, especially if they hibernate in the chimney. A Chimney Sheep® will block moths to an extent but we recommend that you get your chimney swept regularly as part of good chimney management. You can actually reinforce the Chimney Sheep®’s role as a moth blocker by spraying it with Anti Moth Spray with Lavender – this lasts six months so if any visitors think they might try a way in via the chimney they will think otherwise when they get a sniff of the lavender.

Yes you can! We do also have some suppliers outside the UK too.

If you buy a sheep in the shop it will automatically add the required postage for shipping abroad and remove VAT at checkout. For all sizes less than 14 x 28 / 14 x 36 it is £10 for Europe and £15 for the rest of the world. Please be aware that upon arrival, you may need to pay customs charges so please check the charges that apply to your country.

If you are in the USA you can buy our Chimney Sheep® from  Just to be aware, over in the USA we are known as FlueBlocker rather than Chimney Sheep® – exactly the same product but a different name for a different market!

If you are in continental Europe you can buy our Sheep via Amazon Europe too.

For those of you in Australia and New Zealand you can order via our website as we do have stock already in Australia that can be drop shipped. Alternatively, you can order stock on Amazon Australia or through eBay Australia.

To work out what size ‘Sheep you need, you’ll need to measure your chimney and put your measurements into our sizing calculator.

There is no such thing as a universal size chimney draught excluder! These draught excluders are likely to fit a small range of chimneys but won’t be effective for anything outside of those.

Head to our ‘How to measure’ page for an easy step-by-step guide.

This is to ensure easy installation and removal of your Chimney Sheep®. It also means the end of the handle can be seen in the fireplace, stopping anyone inadvertently lighting a fire with your Chimney Sheep® in place. A scenario you definitely want to avoid!

If you head over to our ‘How to measure’ page, there is some advice on how to measure your chimney with a fire surround.

The ‘Sheep works by being a little bit bigger than the flue so it can grip onto the sides and hold itself in place. The amount of overlap doesn’t matter too much as the felt is squashy and can fit into a range of gaps.

Our standard Chimney Sheep® sizes will fit the majority of chimney flues. However, each and every chimney is unique (like us!)  so if your chimney doesn’t look like it will fit one of our standard sizes, contact us with the measurements and we will give you a quote for a made-to-measure Chimney Sheep® that will fit your chimney perfectly!

We just work out the price according to the size of the ‘Sheep but it’s not any more for being tailor made for your chimney. For example, if you needed a 14″ square one it would be a bit more than the 13″ square one but not as much as the 12″ x 20″ one.

Yes, each Chimney Sheep® comes with the correct number of handles needed – the smaller Chimney Sheep need just one, whilst the larger ones will come with two.

Yes, each Chimney Sheep® comes with one 6” extension rod per handle. If you need any more extension rods then you can buy them here.

Just push the wool head into the narrow part of the flue. You may need to tug it down gently to ensure a good fit. That’s it. When you want to remove it, pull gently in case there is any debris collected on it that has fallen down the chimney. Tap any loose soot into the fireplace and put it in a bag.

But don’t worry, you’ll get a step-by-step guide to installation when you get your Chimney Sheep® too!

If you’re not happy with your ‘Sheep then send it back in a re-sellable condition within 60 days for a full refund minus the postage costs. We appreciate that chimneys are hard to measure, but if you are not sure the sheep is going to fit please wrap it in a plastic covering first so it doesn’t get all sooty (take the plastic off once you know it fits).

We are happy to exchange sheep for larger or smaller ones. Please enclose a copy of the purchase order form with a note explaining whether you want a refund or replacement & specify what you want to exchange it for.

If you want to return a bespoke / odd sheep that has been tailor made to your specifications, we do not normally accept returns unless it is due to an error in the sizing on our part. However, we want you to be happy with your sheep so if it doesn’t fit let us know and we will see if an exchange can be arranged.

If you have measured your chimney correctly and used our sizing chart to order the correct size then yes! A ‘Sheep works by being a little bit bigger than the flue so it can grip onto the sides and hold itself in place. The amount of overlap doesn’t matter too much as the felt is squashy, fitting into a range of gaps to ensure that a seal is created.

If you’re not sure if your Chimney Sheep® is going to fit, try it out in its packaging first. We’re happy to exchange your sheep and don’t mind re-packaging it. We don’t much like getting sooty ‘Sheep back though.

If one of our standard sizes doesn’t look right for your chimney opening, we can make you one that’s a neat fit. Chimneys vary enormously, so rather than complicate things by carrying lots of different sizes, we’re happy to do made to measure ones. The price is calculated on the area of the felt needed.

Yes! During hot weather it prevents hot air from entering a property and retains air-conditioned air. It also reduces the number of air changes in a property so considerably reduces the amount of air pollution that enters the home.

Yes it will. However, any soot that is dislodged will just fall into the fireplace. Any loose soot on the Sheep can be gently shaken off into the grate. The wool head will get sooty but when it is not in the chimney it is kept in the log basket or in a bag, so is self-contained.

If it is used regularly the section of chimney it is pushed into will become relatively clean, so there will not be large amounts of soot to worry about. If you did want to remove some of the soot, the best thing to do is just give it a quick hoover. If it becomes too dirty, it can be put in the compost heap and a new head purchased by contacting us directly.

You can buy one of our wraps or put it in a plastic bag. Some people just put it in a coal bucket at the side of the fire.

Please try your best not to do that. Each ‘Sheep comes with its own dangle, or you can buy more decorative ones, but always make sure there is a dangle visible in the fireplace to act as a reminder that there is an obstruction in the chimney. Remember, the person who put the Chimney Sheep® in place isn’t necessarily going to be the person who lights the fire, especially if it is in place for a while.

However, if the worst comes to the worst and a fire is lit with the Chimney Sheep® in place, wool is naturally fire retardant. If it is exposed to a strong flame it will smoulder and give off a bad smell. The fire will not draw properly, and it will quickly become apparent that there is something blocking the chimney. The handle is also fire retardant so it won’t burst into flames or cause a fire hazard.

If the Chimney Sheep® is used somewhere where there may be multiple users, such as a holiday house, make sure the warning card is kept somewhere visible.

When we developed the product, we did try lots of other types of wool. However, only Herdwick wool was coarse and stiff enough to hold its shape when felted. This was important when designing the Chimney Sheep® as it needs to be able to be lodged in a chimney flue and not fall out!

We collect our Herdwick wool from our local farms around Cumbria. We always ensure that the farms we collect them from have high animal welfare standards, so we know that the sheep are well looked after.

They are made here in our factory in Maryport, Cumbria!

Yes! We have lots of people who buy a Chimney Sheep® for this purpose. By plugging the flue, it will ensure your cheeky feline friend stays safe and well away from the inside of your chimney flue.

No matter how long you’ve had your Chimney Sheep®, you can always get in touch with us if you are having issues with it. We are always more than happy to help.