Why & When Should You Hire a Chimney Sweep?

A lot of people are surprised to learn that chimney sweep is still an occupation. They’ve seen old photos of child sweeps in London and Dick Van Dyke’s character in Mary Poppins, of course. But is chimney sweep still a job? Google’s used to answering this question and so are we.

We’re happy to say ‘chimney sweep’ is still a job. We sweep chimneys just about every day! But what else do chimney sweeps do? And when do you need to hire a chimney sweep, and why?

Well, that’s what we’re talking about today.

The Top 4 Reasons to Hire a Chimney Sweep

Chimney sweeps do important work to keep chimneys, furnace flues, woodstoves, and fireplaces clean and in great working order. We’re trained to look for problems that could lead to appliance inefficiency, carbon monoxide exposure, and chimney fires. But we also install fireplaces, stoves, and inserts, and provide services that:

  • protect the exterior of the chimney and keep it standing strong against water and weather
  • prevent animals and birds from nesting in chimneys and creating blockages or fire hazards
  • help with downdrafts and smoky fireplaces
  • and more

So, when should YOU call a chimney sweep? Grab your free cheat sheet here and read on for more details.

#1 When you need to have your chimney swept.

One of the most common reasons to call a chimney sweep is, of course, when you need to have your chimney swept. Let’s talk about why you need to have your chimney swept, how often you should schedule chimney cleanings, what happens if you don’t clean the chimney, and whether or not it’s a DIY job.

Why do chimneys need to be cleaned?

So, why get your chimney swept? Chimneys need to be cleaned periodically because woodburning creates byproducts – like soot and a stubborn deposit called creosote. Creosote is a sticky or candy-like glaze that results from incomplete combustion.

Over time, creosote can build up on the walls of the flue and on the smoke shelf, and because it’s not only corrosive but also highly flammable, if it’s not removed from the chimney, it becomes a fire hazard.

What happens if you don’t clean your chimney?

We get a lot of questions like, ‘What happens if you don’t sweep your chimney?’ and ‘Is a dirty chimney dangerous?’

Well, if you don’t clean your chimney, it’s possible nothing will happen for a long time. But it’s also possible that you’ll experience a devastating fire or carbon monoxide poisoning. Let’s talk about how a dirty chimney puts you at risk for both…

Let’s start with creosote and how it increases your fire risk…

If you have creosote in your chimney when you light a fire in your fireplace, you could soon have a flash fire – a hot, roaring fire that’s fueled by the creosote in the chimney. And while you might think ‘Hey, that’s what chimneys are made for, no big deal,’ it actually is a big deal.

Here’s why: Chimneys are not made to hold fire – they’re made to hold the smoke and byproducts produced by the fire. A chimney fire can actually do a lot of damage to a chimney – and spread fast.

In fact, an overheated terra cotta flue liner can crack within a matter of seconds, creating openings for heat and flames to reach nearby combustibles in walls and framing. That’s why it’s possible for a chimney fire to become a house fire in mere moments.

Now, let’s say you actually have a flue blockage from bird nests, excessive creosote buildup, or some other obstruction. If the smoke produced by the fire in your fireplace is prevented from flowing up and out of the chimney, it can pour back into your home and pollute your air supply. That blockage will also affect the efficiency of your fireplace, and as a result, you could have carbon monoxide entering your home.

This colorless, odorless, tasteless, and toxic gas is very attractive to the hemoglobin in your blood – in fact, your blood prefers CO over oxygen. Pair that preference with the fact that you likely won’t know you’re being exposed to carbon monoxide until you have symptoms (which can often make you feel like you have the flu) and you’ve got a deadly combo.

When should you call a CSIA Certified Chimney Sweep®?

The National Fire Protection Association states that chimneys, fireplaces and vents shall be inspected annually. Just like cleaning out your gutters and changing your furnace filters, make scheduling and annual inspection part of your yearly “To Do List” to keep your home safe and functioning as it should. But when are some other times you should have an inspection scheduled with a CSIA Certified Chimney Sweep®?

If you observe smoke entering your home from your wood fire

If you experience a chimney fire (after the fire department leaves)

If there are conditions that could have damaged the chimney, such as earthquakes or the chimney being struck by debris such as falling limbs

If you smell fumes from your water heater, furnace or boiler

If you notice a brick or stone chimney deteriorating or exhibiting staining

If you see loose mortar in your chimney

If you see rust or corrosion on your metal chimney

When there is a property transaction

If you see any charring or drying on surrounding combustibles, immediatly discontinue use

If something just doesn't look "right"

If you smell smoke

If you hear sounds emanating from your chimney or fireplace, animals or birds may have taken residence

If you notice water or dampness in your chimney or fireplace

Find more information or a professional in
your area today by visiting csia.org

So, yes, a dirty chimney is dangerous. And while there are degrees of dirtiness and degrees of risk, it’s always best to err on the side of caution.

You see, many of us in the chimney and venting industry are former firefighters. We grew weary of seeing the devastating impacts of fires on homeowners and their families – and we decided that we didn’t want to get the call when it was too late. We wanted to prevent fires altogether. It’s why we do the work we do now.

So, don’t take your chances. Have your chimney swept if, and when, it needs it.

How do you know if your chimney needs cleaning?

You may be able to tell if your chimney needs cleaning by looking up inside your flue with a flashlight. Shine the light inside and look for soot and creosote buildup.

We recommend that chimneys be cleaned when an eighth of an inch of sooty buildup is present. And of course, because creosote (which we talked about earlier) is so dangerous, you should have your chimney swept anytime you see a glaze in your chimney, no matter how thin that layer of glaze is.

If you’re looking for a hard and fast rule about when to sweep your chimney (and you don’t want to get on your hands and knees to see what you can see), there isn’t really one. It depends on your appliance, how often you use it, and how efficient it is.

That’s just another reason why we (and the folks at the National Fire Protection Association) recommend that you have your chimney inspected every year by a Certified Chimney Sweep®.

Don’t worry, we’ll get into inspections, what they include, and why they’re needed in just a bit.

What about a clogged chimney – how do you know if your chimney has a blockage?

A clogged chimney may present itself as smoke backup or poor fireplace performance. If you think you may have a clogged chimney, it’s best to schedule an inspection with a Certified Chimney Sweep® before using the fireplace again.

How often should you sweep a woodburning chimney? Do you need to sweep your chimney every year?

Again, there isn’t a hard and fast rule for how often chimneys need to be cleaned. How often you’ll need to have your chimney swept will depend on how much you use it, how efficient the appliance is, and how quickly soot and creosote buildup in your chimney system.

The best thing to do is to schedule an annual inspection with a Certified Chimney Sweep®. This is something we recommend in accordance with the National Fire Protection Association (NFPA) Standard 211, which states:

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

If you keep up with annual chimney inspections, you’ll always know when – and if – your chimney needs to be cleaned.

DIY chimney sweep: can you do it yourself?

Hey, we like saving money as much as the next guy. But there are some things you shouldn’t do yourself. Cleaning your chimney is one of those things. Here’s why you should leave chimney sweeping to an experienced professional:

  • It’s messy if you don’t know what you’re doing. A pro will take great care to protect your property and capture every last bit of soot and creosote in a HEPA vacuum.
  • Soot and creosote are carcinogens and should be handled carefully. There’s actually a Wikipedia page for chimney sweeps’ carcinoma. You don’t want to mess with soot and creosote without the proper tools and PPE (Personal Protective Equipment) – things a pro will have on hand and be comfortable using.
  • Without the right tools, it’s a tough job. The chimney flue is largely hidden from view and it’s hard to get every last bit of the flue and smoke shelf clean without the right tools. Pros have the brushes, rods, and video equipment needed to get the job done quickly. And, if you add up the cost of tools, the wasted Saturday, and the visit to the chiropractor you’ll need when you’re done, it’s just not worth it.
  • You won’t get the eyes of a pro on your chimney. Truth is, there’s a lot that Certified Chimney Sweeps® are trained to look at within the chimney system during a sweeping and inspection. Trained eyes notice issues early on and see things that the untrained eye doesn’t – which means, if you leave the job to the pros, they’ll likely alert you to any issues (if there are any) before they require major, costly repairs.

What’s the best time to schedule a chimney sweeping?

Wondering when to do a chimney sweep? The best time to schedule routine service like chimney inspections and chimney cleanings is during the spring and summer months. If you wait until the fall and winter when you want to use your fireplace, you’ll likely have to wait longer because that’s when everyone remembers they need to have their fireplaces cleaned and inspected.

Another downside to waiting until fall or winter is that, if you need repairs, you may not be able to get them done before the colder months hit.

What about oil-fired appliances and gas furnaces – do they need to be swept? How often?

Most people understand that wood-burning chimney systems need to be cleaned, but they forget about their oil furnace flues, gas fireplaces, and gas furnaces.

Gas appliances certainly burn clean and do not produce creosote and heavy soot deposits like a wood-burning fireplace or stove might. But gas fireplaces and furnace flues still need to be inspected annually and cleaned and serviced from time to time to remove dust and make sure everything is working properly.  Oil-fired furnace flues also need to be cleaned periodically and inspected annually for corrosive buildup, flue blockages, and other possible issues.

The best thing to do is to schedule an annual inspection with a Certified Chimney Sweep®. So, when you’re scheduling routine inspections and cleanings for your fireplace or stove, don’t forget about your furnace flue!

#2 When you need to have your chimney or furnace flue inspected.

Another time to call a chimney sweep is when you need to have your chimney or furnace flue inspected. A chimney inspection is a thorough evaluation of the chimney or furnace flue, and it’s designed to let you know if your chimney system is safe for use or if something – a cleaning or repair – is needed to restore the safety and efficiency of the system.

The NFPA 211 Standard states that every chimney and venting system – whether it’s used or not – should be professionally inspected every single year. But there are other times you may need a chimney inspection as well.

Here’s a rule of thumb around when inspections are needed, per the NFPA:

  • Every year, whether you use the chimney or not
  • When moving into a new home (real estate inspections can give you a negotiating advantage during closing and protect you against hidden damage and dangers)
  • When you notice changes in appliance performance or other issues with your fireplace or furnace
  • When you’re planning a change to your system (a new fireplace, stove, flue liner, or other change)
  • After you’ve had a chimney fire

For more on what goes into an inspection and the three levels of inspections CSIA-Certified Chimney Sweeps® perform, check out our resource piece, What Is a Chimney Inspection & Why Do You Need One Every Year?

#3 When you’re having problems with your fireplace, stove, or venting system.

Of course, chimney sweeps often get called into the home when there’s a problem with the fireplace, stove, or venting system.

Because venting systems and fireplaces involve fire, carbon monoxide, and smoke, it’s always best to discontinue use when you suspect a problem or notice an issue. Once you’ve had a Certified Chimney Sweep® come in and give you the all-clear, then you can start enjoying your fireplace, stove, or furnace again.

What kind of problems mighty you rely on a chimney sweep to fix?

  • Well, maybe you noticed a change in performance and your fireplace just isn’t giving you the heat, clean burn, and high efficiency you’re used to.
  • Maybe your damper is broken, and you want to have it replaced with a top-sealing, energy-efficient damper.
  • Maybe your chimney cap just blew off during a strong storm or you haven’t had a cap on your chimney in years.
  • Maybe you’ve spotted rust in your fireplace or water damage on your chimney’s exterior, and you suspect a leak.
  • Or maybe you’ve had severe weather or another significant event – like a hurricane, earthquake, or tornado – and you want to make sure no damage was done to your chimney system.

These are all great examples of times to call on a professional.

A CSIA-Certified Chimney Sweep® will be trained and qualified to tackle these issues and any other problems you might be experiencing. And because they’ve passed extensive examination, invested in continued education, and agreed to conduct themselves in accordance with our Code of Ethics, you can be confident the recommendations they make and the work they do will be in your best interest, not theirs.

#4 When you’ve had a chimney fire.

Lastly, if you’ve had a chimney fire or think you may have had one, call a chimney sweep. A chimney sweep will come in, assess the damage, look for what may have caused the fire, and recommend any needed cleanings and repairs.

How do you know if you’ve had a chimney fire?

  • Some fires are obvious – they sound like a freight train coming through your living room, popping and cracking as they blaze. With these types of fires, you might notice large plumes of smoke coming through your fireplace opening or out of your chimney. You may also notice flames or sparks coming out of the chimney top.
  • Some fires burn slow and steady, so you might not even know there’s a fire occurring in your chimney. With these, you’ll look for things like ashy creosote chunks in your fireplace or on your roof, broken flue tiles in your fireplace, warped metal components (like your damper or chimney cap), and cracked masonry on your chimney’s exterior.

Of course, if you schedule a level two inspection with a CSIA-Certified Chimney Sweep® every year, they’ll perform a video scan of your flue and will be able to tell you if you’ve had a chimney fire as well.

Note: If the fire is active, the first thing you want to do is call the fire department. Once the fire is put out and you’ve been cleared to return to your home, that’s when it’s time to call a chimney sweep.

Time to Hire a Chimney Sweep? Choose From the Best

So, there you have it: the top four reasons to call a chimney sweep. We hope this content has been helpful to you. If you have any other questions for us that you don’t see answered here on our site, just reach out at 317-837-5362 or at office@csia.org. We’re here to help.

In the meantime, if you need a chimney sweep you can trust, choose from the industry’s best.


have questions about what to look for when hiring a chimney sweep, you’ll find some answers in our Homeowner Resources  section.