Why should you clean your chimney?
You may have been recommended to clean your chimney, but you don’t understand why. Really, it is preventative to ensure your safety.
When you use your wood fireplace or oil appliance, soot naturally builds up inside the chimney. You want to address this soot buildup, as it can catch on fire. You also want to detect for the potential of carbon monoxide (an odorless and toxic gas), heat, or smoke leaking into your home. This is possible if your chimney has large holes or cracks behind the drywall.
The same applies for gas appliances. They can produce carbon monoxide, and any large holes or cracks may allow carbon monoxide to leak inside the chimney cavity and potentially the drywall area of the home.
How often should I clean my chimney?
We highly recommend at least an annual cleaning, especially before you plan to regularly use your fireplace in the winter months.
What terms should I know?
- Flue: the duct, pipe, or opening in the middle of the chimney, though which smoke and gases are carried outdoors.
- Damper: this is what is intended to shut off, fully or partially, the chimney flue. It helps control and slow your fire.
- Creosote: It is a corrosive material that is produced by gases given off as the word burns in your fireplace. It is a leading cause of fires, as it is combustible and it can small as well. It naturally builds up, and must be cleaned out regularly.
How do you clean a fireplace?
For a basic cleaning, you will need to remove the grate and andirons from your fireplace. You’ll want to scrub them with a nylon brush, and then rinse with water and wipe dry. For the fireplace itself, you’ll want to shovel out the ash and debris in your fireplace. Once this is done, you can then scrub the walls with the nylon brush as well. We recommend placing newspaper or something at the floor, to collect the soot as you’re scrubbing.
For deep-cleaning and to ensure there have been no major leaks or cracks forming, we highly recommend hiring a professional service. Give us a call to find out more!
We trust the word of the CSIA, and thus we’ve provided additional resources here to answer any additional questions.
FAQs direct from CSIA.org
Q. How often should I have my chimney swept?
This a tougher question than it sounds. The simple answer is: The National Fire Protection Association Standard 211 says, "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." This is the national safety standard and is the correct way to approach the problem. It takes into account the fact that even if you don't use your chimney much, animals may build nests in the flue or there may be other types of deterioration that could make the chimney unsafe to use.
The Chimney Safety Institute of America recommends that open masonry fireplaces should be swept at 1/8" of sooty buildup, and sooner if there is any glaze present in the system. This is considered to be enough fuel buildup to cause a chimney fire capable of damaging the chimney or spreading to the home. Factory-built fireplaces should be swept when any appreciable buildup occurs. The logic is that the deposit is quite acidic and can shorten the life of the fireplace.
Q. My fireplace stinks, especially in the summer. What can I do?
The smell is due to creosote deposits in the chimney, a natural byproduct of woodburning. The odor is usually worse in the summer when the humidity is high and the air conditioner is turned on. A good sweeping will help but usually won't solve the problem completely. There are commercial chimney deodorants that work pretty well, and many people have good results with baking soda or even kitty litter set in the fireplace. The real problem is the air being drawn down the chimney, a symptom of overall pressure problems in the house. Some make-up air should be introduced somewhere else in the house. A tight sealing, top mounted damper will also reduce this air flow coming down the chimney.
Q. When I build a fire in my upstairs fireplace, I get smoke from the basement fireplace.
This has become quite a common problem in modern air tight houses where weather-proofing has sealed up the usual air infiltration routes. The fireplace in use exhausts household air until a negative pressure situation exists. If the house is fairly tight, the simplest route for makeup air to enter the structure is often the unused fireplace chimney. As air is drawn down this unused flue, it picks up smoke that is exiting nearby from the fireplace in use and delivers the smoke to the living area. The best solution is to provide makeup air to the house so the negative pressure problem no longer exists, thus eliminating not only the smoke problem, but also the potential for carbon monoxide to be drawn back down the furnace chimney. A secondary solution is to install a top mount damper on the fireplace that is used the least.
Q. I heat with gas. Should this chimney be checked too?
Without a doubt! Although gas is generally a clean burning fuel, the chimney can become non-functional from bird nests or other debris blocking the flue. Modern furnaces can also cause many problems with the average flues intended to vent the older generation of furnaces. We suggest you check the areas on gas and carbon monoxide for more information.
What you have described sounds pretty typical. In addition to the chemical treatment that you mentioned, professional-grade chemicals, usually in the form of a powder, can be applied by chimney sweeps to help change the nature of the glazed creosote to a form that can be removed by a professional with a brush Both forms of these products require some heat such as you would find in a small fire in the fireplace. If the creosote is gummy, about the only way to deal with the creosote is with a chemical treatment or with an acid application. Acid applications are not as commonly used since they are harder to apply and have to be neutralized a few days after application. If the creosote is crusty or fractures when hit (as opposed to gummy) a rotary cleaning can be helpful. Read our position statement on chemical chimney cleaning products here.
More on creosote: What it looks like [watch the video]
Your past experiences with chimney sweeps sound as though the sweep did the job he was hired to do. However, your most recent experience sounds a bit odd. If the sweep agreed to do a complete sweeping and only cleaned the brick in the fireplace firebox, you did not get the service that you paid for. A complete chimney sweeping includes the chimney flue and smoke chamber.
In the future you could ask for a Level 1 chimney inspection and a chimney sweeping. If the sweep doesn’t know what a Level 1 inspection is, find one that does. A Level 1 inspection is detailed in the National Fire Protection Association 211: Standard on Chimneys, Fireplaces, Vents and Solid Fuel-Burning Appliances.
Q: How common is it that chimney liners cannot be seen from inside the fireplace using only a flashlight?
Flues are allowed to have up to 30 degree offsets. In most cases this will make a direct visual observation of the flue impossible. A video scan would be required to evaluate the flue condition. The height of the chimney flue is not a factor. There is a big difference in what is observed between a visual inspection and a video inspection, even in short flues.
Additional questions: Q: What's safe to burn in the fireplace?
Watch the video below to see what happens when you burn holiday wrapping paper, a pizza box, and foam packaging.
This is a common question. If the damper is not functioning correctly or if it’s closed, you’ve got a situation on your hands that may lead to a smoky room at best and a fire hazard at worst. The damper is a hinged metal plate or valve used to seal the fireplace when not in use. You want the damper to be fully open, and you want it to be in the open position before you light your fire, for obvious safety reasons."
The Chimney Safety Institute of America (CSIA), a non-profit, educational institution focused on the prevention of chimney and venting hazards, is concerned about the consumer use of chemical chimney cleaning products to the exclusion of conventional chimney inspections and cleaning. These products often are promoted for their ability to remove a portion of the creosote from a masonry or metal chimney interior through catalytic action when burned in a fireplace or wood stove. The CSIA believes that the use of these products alone is not an adequate substitute for mechanical chimney cleaning and inspection because it does not provide the same level of protection to the chimney system. Current promotional claims for some of the products may be creating a false sense of security among consumers.
It is the consensus of qualified experts that chimney maintenance is best achieved through annual inspections, and mechanical sweeping, by trained professional chimney sweeps as frequently as needed. Chimney inspections often reveal hidden problems with a chimney structure that could be potentially hazardous. Mechanical sweeping of chimneys not only removes layers of creosote from the chimney surface, it removes the resulting loose soot and creosote from the chimney, fireplace, or wood stove. A substantial percentage of fireplace and wood stove chimneys do not provide a straight path from the firebox to the outside. If chemical chimney cleaning products perform as claimed and cause debris in the chimney to fall, that debris still needs to be removed from the smoke shelf, baffle, catalytic combustor, or offset in order to ensure a properly functioning chimney.
Chemical products that claim to clean or assist in cleaning chimneys are not new. Indeed some of these chemical products are used successfully by professional chimney sweeps in conjunction with the mechanical cleaning of a chimney. In some situations a chimney can develop a hard or tacky layer of creosote in the chimney that cannot be removed by normal mechanical brushing. Under the supervision of a qualified chimney professional certain chemical cleaners may be used to change the chemical composition of the hard or tacky layer of creosote into a brittle or powdery condition to facilitate its removal.
CSIA believes that the optimal method for cleaning a chimney is by a mechanical brushing of the chimney in conjunction with a complete evaluation of the system by a qualified chimney professional. The CSIA and the National Fire Protection Association recommend annual inspections.