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Safety Tips

Fuels: Correct Fuel, Correct Use

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It is very important to burn the correct fuels on your solid fuel appliance. Using the right fuel will help keep your fire and chimney in a good, efficient condition. For full information on

The chimney liner and fuel must be compatible. Using the wrong type of fuel on a liner will reduce the life of the liner considerably due to increased corrosion. This can create a dangerous situation.

Wood fuel must be dry, about 20 per cent moisture or less. Burning wet wood produces poor heat, more pollution and can block the chimney. The risk of chimney fire will also increase.

Beware of the phrase, ‘seasoned wood’. The key factor is the moisture content (it must be 20 per cent or less).

How you store your wood is important. It’s best kept in a dry store with good ventilation allowing air to get round it. Stacked well ventilated logs will continue to lose internal moisture. The best log store will be under a shelter that keeps the rain off but allows plenty of air to circulate.

If the wood is not kept well aired then it will slowly decay. It will have a reduced heat output and may take on moisture.

Using wrong or poor quality fuel is bad for your chimney, bad for the environment and bad for your wallet.

Help raise awareness by sharing the video below:


It is very important to allow your solid fuel appliance to breathe properly to allow the chimney to take away the fumes effectively. Inadequate ventilation to the room can lead to smoke curling back down the chimney or a slower gas emission rate. The chimney can soot up much faster. Insufficient air flow will also lead to incomplete combustion, resulting in potential increased levels of carbon monoxide.

Be aware of powerful air extractors like cooker hoods and fans. They fight with the air trying to get up the chimney and can cause fumes to enter the house.

Ventilation requirements

Open Fires

In the case of an open fire with or without boiler, air opening/s should allow for a total free area of at least 50 per cent of the throat opening area. This is usually 16500 mm2 for a typical open fire.

Closed Appliances

If the house was built after 2008 then an air vent needs to be fitted that is 550mm2 per KW. So an 8KW stove in a new build would need an air vent about 4400mm2 or as advised by the appliance manufacturer – whichever is the greater.

NOTE: It is sometimes necessary to fit an air vent in an older property with a 5KW stove if there is not sufficient air to the room or, if the property had undergone significant draught proofing or heat loss prevention measures such as double glazing, cavity wall insulation, etc.

Your Guild sweep will be able to advise you on your ventilation requirements.

Preventing Chimney Fires

There were about 5,000 reported chimney fires in the period 2014 to 2015. The real number would be far greater as many fires don’t result in an emergency call. Guild sweeps are also aware that some customers can have smaller chimney fires without realising it ever happened. That can be the case if the chimney fire was slow and quiet. Other chimney fires can burn explosively – noisy and dramatic enough to be detected by neighbours or passers-by. Flames or dense smoke may shoot from the top of the chimney. Chimney fires don’t have to happen, follow the advice on

A fierce chimney fire will most likely cause damage. This damage may not be apparent at first and everything may seem fine. Do not use the appliance/chimney until a full survey has been carried out and a report produced. This will often require the use of specialist CCTV surveying equipment

Chimney fires don’t have to happen. Here are some ways to avoid them:

If you burn right you will have much less chance of a chimney fire. Go to  to learn how to “Get it Right”.

Use wood fuel  with a water content of less than 20%. A moisture meter is very useful.

Build hotter fires that burn more completely. Don’t be tempted to slow it all down to ‘save fuel’. Slumbering the fire is the worst thing you can do.

Never burn cardboard boxes, waste paper or Christmas trees. These can start a chimney fire as bits can get sucked up the flue, setting fire to any soot or tar in the chimney.

Burn recommended fuels ONLY and NEVER use your fire for waste disposal. This can start chimney fires and produces toxic chemicals.

If you are unsure, check the manufacturer’s instructions or ask your stove supplier. Your local fuel merchant may also be able to give you advice as well as, of course, your Guild sweep.

If you have a thatched property, it is very important to follow your insurance company recommendations and Local Authority guidelines.

Make sure you are aware of the frequency that your chimney must be swept in order to comply with your insurance policy. Your Guild sweep may advise a more regular sweeping frequency than your insurance company requires depending on your situation and what they find in your chimney.

Damaged Chimneys – Stacks, Liners, etc

The two main reasons for damage to a chimney stack are:

  • A chimney fire
  • Weathering with age

A chimney is built in the most exposed part of the house. Sun, wind, rain and frost weathers it for years, and then we light fires underneath and fill it with corrosive soot, which eats away at it from the inside. It is no wonder that it needs maintenance from time-to-time.

It doesn’t help that chimneys are built on top of houses – where the homeowner is less able to see any problems. It’s when things go wrong that an inspection is made and by this time it’s too late: damage has been caused. Regular inspections by Guild sweeps are the solution – he or she will perform visual checks the structure that can help identify issues before they become more serious.

Damage to the chimney stack and flue can affect the performance of your chimney and reduce its ability to remove harmful combustion gasses. Flue damage can also allow leakage of poisonous gasses to bedrooms or the loft area which can result in injury or death in extreme cases. Following a chimney fire, the Guild strongly recommends that a full survey is carried out on the installation and flue before it is used again. If a chimney has not been used for many years it also makes sense to have it surveyed.

There are a fair number of Guild members who have the required training, equipment and insurance to undertake this work for you. See their individual profiles for services offered.

The chimney/flue terminals pictured below MUST NOT be used on any live appliance. They are for redundant chimneys only.

Doc J – Building Regs

Approved document J is the section of the building regulations that relate to heat producing appliances in domestic properties. It has sections for solid fuel, gas and oil. Your local Guild sweep is trained in all aspects of document J that relate to your fire/woodburner and chimney and will be able to give you guidance.

Click here to download Document J