Keeping your chimney safe

Introduction

A warm fire can make any home feel welcoming, especially in the colder months. But behind that comfort lies an important responsibility – chimney safety. Poorly maintained chimneys are a major cause of house fires every winter in the UK, yet most are preventable with simple, regular care.

This guide explains how to keep your chimney safe, what maintenance is required, and how to reduce the risk of chimney fires or carbon monoxide poisoning.

Why Chimney Safety Matters

Each year, thousands of chimney fires occur in homes across the UK. According to the National Fire Chiefs Council (NFCC), fire and rescue services attend around 3,000 to 4,000 chimney fires annually, most of which start because chimneys haven’t been cleaned or maintained properly.

Beyond fire risks, poorly ventilated chimneys can allow dangerous gases such as carbon monoxide to enter living areas. Carbon monoxide is colourless and odourless, making it impossible to detect without an alarm. Every home that uses an open fire or wood-burning stove should have a carbon monoxide detector fitted nearby.

Common Causes of Chimney Fires

Most chimney fires begin with creosote, a flammable tar-like substance that builds up when wood or coal isn’t burned completely. Other contributing factors include:

• Infrequent or missed chimney sweeping
• Burning wet or unseasoned wood
• Using resinous woods such as pine, which produce more soot
• Leaving fires smouldering overnight
• Incorrectly sized stoves or flues

By recognising these risks early, you can take action before they cause serious damage.

How Often Should You Sweep Your Chimney?

The frequency depends on the type of fuel you use. Professional chimney sweeps generally recommend:

• Wood: Up to four times a year
• Bituminous coal: Twice a year
• Smokeless coal, gas or oil: Once a year

Always use a qualified professional registered with recognised bodies such as The National Association of Chimney Sweeps (NACS), APICS or HETAS. They can spot early signs of structural issues, blockages or damage to chimney liners.

Safe Burning Practices

The way you use your fireplace or stove makes a big difference to safety and efficiency:

• Use seasoned wood: Burn logs with a moisture content of 15–20%. Wet wood produces more smoke and creosote, while overly dry wood burns too quickly and hot.
• Avoid treated or painted wood: These can release toxic fumes and damage your flue.
• Let the fire burn down naturally: Before bedtime or leaving the house, spread out the embers, cover them with ash, and close the air vents. Avoid dousing with water unless necessary.
• Keep the area clear: Maintain at least one metre of space around open fires or stoves, and use a fireguard to protect children and pets.

Spotting Chimney Problems Early

Regular observation can prevent larger issues. Contact a professional if you notice:

• Excessive smoke or a strong tar smell
• Falling debris, soot or flakes in the fireplace
• Discoloured walls or ceilings near the chimney
• Cracks in the chimney breast or flue
• Smoke backing up into the room

Never attempt to repair chimney structures yourself, always seek professional advice to ensure it remains safe and compliant with UK building regulations.

What to Do if You Suspect a Chimney Fire

If you think your chimney has caught fire:

• Call 999 immediately and leave the property if you are at risk.
• Close the stove door or fireguard to reduce air flow.
• Do not pour water on a chimney fire, it can cause cracking in the flue.
• Afterwards, arrange a full inspection before using your fireplace again.

More advice is available from your local fire and rescue service or the Fire Kills campaign.

Does Home Insurance Cover Chimney Fires?

Most home insurance policies cover fire damage as standard, including chimney fires. However, insurers may refuse a claim if the fire was caused by neglect or poor maintenance. Regular sweeping, use of appropriate fuel and professional installation all help demonstrate responsible upkeep, which can make a difference if you ever need to claim.

If you own an older or unusual property, check that your insurer covers non-standard construction and heating systems. You can learn more about this on our non-standard home insurance page.

Further Reading

Keeping your chimney clean is just one way to prepare your home for the colder months. For more practical advice, read our article: Is your home ready for winter?