What is a chimney fire?
Chimney fires happen when soot or creosote deposits in the chimney catch light due to high temperatures or flames from a very hot fire extending into the outlet. These types of chimney fires are sometimes associated with:
- A loud roaring noise, the result of massive amounts of air bring sucked through the burner or fireplace opening
- Sparks and flames seen shooting from the chimney top, which can be similar to fireworks in appearance
- A glowing or shimmering outlet or connector
- A vibrating appliance, outlet or connector
- Flames visible through any tiny cracks in the outlet or connector
- Smoke or smells noticeable in adjoining rooms or the loft space
- The chimney breast of flue pipe heating up in either the same room or other rooms they pass through.
It should be noted that it is possible to experience a chimney fire without any of these characteristics so this should be treated as a guide.
All chimney fires are extremely dangerous – internal flue temperatures can reach 1,100 degrees Celsius. As a result, massive radiant heat is emitted through the chimney walls and, with the addition of a thatched or wooden roofs, a devastating house fire can start quickly. Flames and sparks can leap from the chimney top or through cracks in the flue and ignite the roof or other parts of the house. The bricks of the chimney can become hot enough to combust nearby flammable materials such as thatch and wooden beams. Adjoining houses and nearby trees can also be affected.
If there is no apparent damage to the outside of the chimney breast or flue, it is still highly likely that there is damage to the lining of the chimney. Chimney fires burn hot enough to damage liners, crack chimney walls and pots and damage factory-built metal chimneys.
Always make sure that you have a working smoke alarm fitted to each floor of your house. They help save lives by giving you earlier warning of a fire and extra seconds to get out. Make sure you have an escape plan in the event of a fire.
What to do if you have a chimney fire
- Call the fire service – 999 if you are at all worried for your safety then Get out and Stay out.
- If you have a stove then shut all air vents and flue dampers to reduce the chimney fire’s oxygen supply.
- Move flammable materials, furniture, ornaments away from the fireplace.
- Feel the chimney breast throughout the house – if it is getting hot then move furniture away from it.
- Do not pour water on the fire if you have a stove.
- Do not pour salt on the fire – this can create chlorine gas which is damaging to the chimney and toxic if it gets into the room.
- Make sure firefighters can access the loft space.
Preventing Chimney Fires
There are four main reasons for chimney fires happening:
- Infrequent sweeping and cleaning
- Burning unseasoned wet wood
- Improper appliance sizing
- Overnight burning or smouldering wood for long periods in wood burners.
To reduce the risk of a chimney fire, you should:
- Have you chimney swept on a regular basis by a qualified and competent sweep.
- Make sure all wood burnt has a moisture content below 17%. Burn only well seasoned wood.
- Choose the correct size of appliance for your room. One wjich is too big will not burn all of the fuel in the wood. The unburned fuel will pass up the chimney in the smoke, condense and form as extremely flammable creosote.
- If you have a stove always follow the manufacturer’s recommendations for fuel loading and air flow.
Anyone that has a flued appliance has a responsibility to maintain the appliance and the flue. It is often stated that people should take reasonable care within the terms of household insurance policies and, in the case of thatched properties, the frequency of sweeping is often specified by the insurers.
If you are in a rented property, your landlord has a duty of care towards you as a tenant ‘to repair and keep in any working order, any room heater and water heating equipment’.
Sweeping your flue/chimney removes deposits which have built up due to the burning of carbon-based fuels, such as coal, wood, oil and gas. It makes sure there is a clear and safe passage for gases caused by the burning process, which are combustible, making the risk of the chimney catching fire less.
Sweeping will also mean that objects such as nests, cobwebs and loose brickwork, which could obstruct the chimney, are also removed.
For further technical information on chimney sweeping and to locate a registered sweep please visit: