How Often Chimney Needs Sweeping

Here’s How Often Your Chimney Needs Sweeping (And Why)

In Chimneys, Indoor Fireplaces by James O'KellyLeave a Comment

Using your fireplace regularly can quickly start to make your chimney dirty with soot, ash, and other small particles from the fires, and can mean your chimney often needs sweeping.

Unfortunately it’s not particularly easy to check whether your chimney needs sweeping. Your fireplace may look clean but your chimney may not be in the same condition. A dirty chimney can prevent harmful gases from leaving your home even cause chimney fires in the most serious of cases.

So to prevent the build-up of dirt, how often does your chimney need sweeping?

You should get your chimney inspected or cleaned at least once a year for all types of fireplaces. If you regularly burn wood or coal in your fireplace, you should sweep your chimney every season.

Each fireplace and chimney is different and so it’s important to understand the  signs that your chimney need cleaning, why a chimney needs sweeping, and the dangers that can arise from not sweeping your chimney.

How Often Your Chimney Needs Sweeping

The National Fire Protection Association (NFPA) states under Standard 211 (2019) for Chimneys, Fireplaces, Vents, and Solid Fuel-Buring Appliances, that:

“Chimneys, fireplaces and vents shall be inspected at least one a year for soundness, freedom from deposits, and correct clearances. Cleaning, maintenance, and repairs shall be done if necessary.”

For residents of the United Kingdom, the National Association of Chimney Sweeps (NACS) note that factors including the type of chimney, type of fuel, how long the fireplace has been used, type of appliance, and the moisture content of wood will all determine how often your chimney need sweeping. However, they recommend that, as a guide, these cleaning frequencies should be followed:

  • Every quarter when regularly burning wood or coal in your fireplace
  • At least one a year when smokeless fuel is used
  • Once a year for both oil and gas fireplaces

The solid fuel safety and standards organization, HETAS, also encourages having your chimney swept at least once per year when burning smokeless fuels, but recommends at least twice a year when burning wood or coal.

How to Know When Your Chimney Needs Sweeping

In the first instance you should follow the guidance outlined above that have been set out by recognized institutions for your area. That way you can rest assured that you’ve followed the best advice for maintaining your chimney.

It’s likely that your chimney will be used more in the winter months than at other times of the year, so set a reminder on your phone to have your chimney swept, or at least inspected, every year before winter.

If you haven’t used your fireplace for a prolonged period of time, be sure to have your chimney swept before starting to use it again.

Lastly, if you have just moved into your house, check to see if you can find any documents that show when the chimney was last cleaned. If you aren’t sure when it was last swept, it may be worth getting your chimney inspected and cleaned as a precaution before you start using it.

7 Quick Signs Your Chimney Needs Cleaning

1) You can smell smoke in your home after a fire
2) Your fireplace surround is starting to turn black
3) Your fires aren’t burning as strongly and burning wood creates more smoke than usual
4) Strong smell coming from the fireplace
5) Soot is dropping down into the fireplace.
6) Animals are nesting in the chimney
7) Visible deposits of black particles within the chimney

What Happens if You Don’t Clean Your Chimney

Through use of your fireplace your chimney can build-up with soot and other tiny particles. Over time, this can cause the chimney to become smaller and be less efficient at drawing smoke and gases out of the fireplace.

Fireplaces, especially wood and gas, can release harmful gases as a result of the combustion process, such as carbon dioxide and carbon monoxide.

It’s therefore very important that these gases are vented out of your house, as a blocked chimney can prevent the gases from leaving and instead make their way into your home.

The highly flammable material creosote can also build up within in your chimney from burning wood. Creosote can increase the risk of developing chimney fires that can potentially lead to structural damage of your chimney.

There may also be other blockages in the chimney such as bird nests that can increase the risk of a fire starting in your chimney.

A partially blocked chimney can also lead to blackening of your fireplace, where soot from the fire rises out into your home rather than up the chimney.

Does a Lined Chimney Need Sweeping?

A lined chimney contains a metal, ceramic or clay duct that vents gases and/or smoke direct to the atmosphere outside.

A lined chimney works in the same way as a regular chimney and so should also follow the minimum recommended cleaning intervals outlined above.

The type of flue will dictate how often it should be cleaned. Speak to your chimney sweep or check your fireplace appliance manufacturer’s guidelines for advice on how often it should be swept.

How Much Does Chimney Sweeping Cost?

A survey by HomeAdvisor found that the average cost of having your chimney swept is $240, with the typical cost ranging from $126 to $356.

I the UK, having your chimney swept can cost anywhere between £30 and £80 for a standard clean from your fireplace, but expect to pay a bit more if you are living in London.

If there is damage to the top of your chimney, such as damage to your cowl, you will most likely have to pay extra for any work that requires access via a ladder or scaffolding from the outside of your house.

If your chimney sweep has to travel further to reach your home, expect that cost to be reflected in the quote.

The cleaning should take anywhere between 20 minutes to an hour and a half. The actual time will depend of how large, how tall, how many chimney stacks your house has and if there are any abnormal blockages.

Preparing For Your Chimney or Flue to be Cleaned

Your chimney sweep will need clear access to your chimney from your fireplace so make sure that your mantelpiece and hearth are clear of ornaments and any other items, just to be sure that nothing gets dirty or broken.

You should also clear up any left over ash, wood, burnt logs or other types of fuel from your fireplace so that the chimney sweep can get on with cleaning straight away.

If you know that your chimney is really dirty or just aren’t sure of its condition, it may be worth covering your furniture and carpet or rugs near the fireplace will old sheets. If any soot happens falls down the chimney during cleaning then you’ll have piece of mind that your home is protected.

Do You Need a Chimney Sweep Certificate?

Your chimney sweep should provide you with a certificate upon completion of the work.

It may be the case that a certificate is required by your home insurance. It’s probably worth spending a few minutes of your time to check!

Does Chimney Sweeping Make a Mess?

Your chimney sweep will take the upmost care to make sure that as little mess as possible is made when cleaning your chimney.

Although every precaution will be taken, there may be some circumstances where soot will fall down from the chimney into the fireplace.

As mentioned, be sure to cover any furniture and the surrounding areas with old sheets just to be on the safe side.

I Have a Gas Fireplace Do I Need to Sweep the Chimney?


Your gas fireplace appliance should be checked regularly by a professionally qualified engineer. The engineer will check to see if your chimney is providing a sufficient amount of draw, and advise whether your chimney should be cleaned if not.

Tips for Reducing How Often Your Chimney Needs Cleaning

  • Use your fireplace less (obvious I know!)
  • Burn harder wood logs. Using softwood such as pine in your fireplace increases the rate of build-up of creosote in your chimney.
  • Burn well-seasoned wood
  • Invest in a newer, more efficient fireplace appliance
  • Get your fireplace appliance serviced and/or cleaned. A poorly operating appliance will increase the rate of creosote accumulation.
  • Use a recommended and registered chimney sweep to ensure that your chimney is receiving the highest level of service.

Keeping Your Chimney Clean

Staying on top of your chimney cleaning will help prevent any unwanted problems further down the line, and can prove to be the most cost-effective and safest solution for your home.

As with many problems, the longer you leave your chimney to be cleaned the worse it may become. Be sure to book a chimney sweep if you don’t think your chimney has been cleaned within the last year.

How often do you have your fireplace cleaned? And how much do you usually pay? Let us know in the comments below. It would be great to hear from you!

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