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Help & Advice

When should I have my chimney swept?

It’s important to have your chimney swept regularly. Annually across the UK we are seeing declines in instances of chimney fires, between April 2019 and March 2020 there were 3,130 chimney fires in England.

Our team is often asked “When should I get my chimney swept?”

We encourage having your chimney swept at least twice a year when burning wood or bituminous house coal and at least once a year when burning smokeless fuels.

The best times to have your chimney swept are just before the start of the heating season and after your stove has not been used over a prolonged period. If sweeping twice a year, the second time should be after the peak of the main heating season.

Why Do You Need to Sweep Your Chimney?

Sweeping your chimney is a vital part of owning a stove or fireplace. Even if you have a chimney liner, a regular sweep is essential for getting rid of any blockages or debris that can put you at risk of a chimney fire. A professional chimney sweeper will also be able to look out for any other hazards you may be unaware of. This could be cracks or other repair works that need doing to keep your stove running at its best and safest.

It doesn’t matter what type of chimney you have – brick, clay, twin wall or lined, they will all need regular sweeping.

Do Gas Stoves Need a Chimney Sweep?

Yes, if you have a gas stove or fireplace, your chimney will still need sweeping, but less often. While gas isn’t a solid fuel that gives off smoke, it’s still an important safety measure. A gas fire flue acts as an exhaust pipe that removes carbon monoxide from your home. If it becomes blocked, it might build up to a dangerous level. If you have a gas stove, an annual maintenance check is extremely important, so make sure you do it!

How Often Should You Sweep your Chimney

You should have your chimney swept at least once a year as a bare minimum. This ensures your chimney is kept as clean as possible and prevents buildup that will become harder to remove if you leave it. Many people choose to get their chimney swept at the end of summer so that it is ready for the colder temperatures ahead.

Any more than this depends on how often you use your stove or fire. If you use your stove heavily throughout winter, your chimney sweep might recommend further visits, particularly if your chimney is very dirty.

You should always contact a reputable chimney sweep to be sure you’re getting the best advice and service. The Association of Professional Independent Chimney Sweeps is a reliable source of chimney sweeps.

If you are using your stove or chimney for the first time, you should always get it swept and inspected before you do anything.

How Do You Know When Your Chimney Needs Sweeping?

An annual chimney sweep is a good place to start, but you need to keep an eye out for signs that your chimney is getting too dirty in between. Your chimney sweeper may advise you on when your next sweep should be, but you can also look out for these signs yourself:

  • Smoke is being blown back into the room
  • There is a bad smell even when you haven’t lit a fire
  • You can see signs of tar around the damper or flue entrance
  • Soot is frequently falling back into your stove or fire
  • Your fire isn’t burning as well as usual
  • You can see birds around the top of your chimney or hear scratching – there may be a nest

If you notice any of these signs, a chimney sweep or inspection is probably necessary. If you want to check the inside of your flue or chimney yourself, make sure you wear goggles and a dust mask. Then, get yourself a torch and shine it up the inside of the firebox. If you see any black build up, try to scratch away at it – if it is around a quarter of an inch thick, it’s best to not use your stove until you get your chimney swept.

What Happens If You Don’t Clean Your Chimney?

If you don’t clean your chimney, you are putting yourself at risk of chimney fires and carbon monoxide poisoning. The build up of soot, creosote and tar can block fumes from escaping and ignite under heat.

Without inspection by a professional chimney sweep, cracks and corrosion could also lead to other flammable debris falling into your chimney. Cracks can also lead to you getting damp in your chimney, which can cause a number of problems in your home.

What is Creosote and What Causes it in a Chimney?

Creosote is a thick black substance that is caused by burning solid fuel. It forms when fire is burnt too slowly or burns incompletely. When the smoke cools and sticks to your chimney wall it turns into creosote.

You may see creosote in a number of different forms, such as the following:

  • Light soot – this isn’t a huge problem as long as you get your chimney swept regularly. It should be easy to remove with the correct brush.
  • Sticky tar-like substance – if you see this form of creosote, it is much more cause for concern. It can be difficult to remove and may require chemical cleaning.
  • A hard and thick layer – the most dangerous form and almost impossible to remove. This form of creosote can easily cause a fire, so don’t use your chimney if you see it until you’ve consulted a chimney sweeper.

If you begin to find an excessive build-up of creosote, you might be burning your fire incorrectly. Read the tips below to find out what you might be doing wrong…

How Do I Stop Creosote Build Up In My Chimney?

Preventing creosote build up in your chimney is often easier than removing it. Luckily, there are a number of things you can do to stop creosote becoming a problem:

  • Avoid a slow burning fire. These give off more fumes.
  • Use the right fuel. Dry seasoned wood or smokeless fuel are the cleanest options for your stove. Remember,  multi-fuel stoves are the only stoves you can burn smokeless fuel in.
  • Make your fire hot and give it plenty of air. This helps fuel burn most efficiently.

Use a Professional

We recommend that chimney sweeping is best carried out by a qualified Chimney Sweep, like Chim-Me-Sweep.  In order to maintain high standards of sweeping, we are associated with these professional bodies: The Guild of Master Chimney Sweeps (GoMCS), The National Association of Chimney Sweeps (NACS) and Sweep Safe.


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