Chimney Essentials

Should I have a chimney liner installed?

    • Stainless-steel liners can be installed in masonry chimneys to correct internal damage caused by a chimney fire. A qualified chimney sweep should inspect your existing masonry chimney before your wood-burning appliance is installed.
    • Masonry chimneys must have a liner made of clay tiles, firebrick or stainless steel to be suitable. It is advisable to upgrade old, unlined chimneys by installing a certified stainless-steel liner.
    • Air-Cooled Chimneys – Some decorative factory-built fireplaces are approved for use with chimneys that use air flow, instead of solid insulation between inner and outer layers, to keep the outer surface cool. Never connect wood-burning heating appliances to air-cooled chimneys, or flue gas will cool excessively.

How often should I get my chimney cleaned?

    • If you use your fireplace 2-3 times per week during the burning season, you should have it cleaned & inspected annually for safety. 
    • Dirty chimneys can and do cause house fires. In fact, 1 in 8 fires are due to improper maintenance & cleaning of chimneys.
    • Ideally, chimneys should be cleaned in the spring to remove toxic odours that can enter the home.
    • It takes about 1 hour to clean a chimney properly.


What about creosote?

    • The residue from burning fire logs is called creosote which over time forms a thick coating on the firebrick inside your chimney. It is highly flammable if allowed to accumulate and can create the conditions for a chimney fire if not cleaned regularly and properly.
    • Many people are very sensitive to this form of indoor air pollution.
    • To ensure less smoke, burn only clean, well-seasoned wood that has been split and dried properly. Dry wood lights faster, burns better and produces much less smoke than "green" wood, a major factor in creosote accumulation.
    • Never burn wrapping paper or cardboard as this may produce sparks that can ignite excess creosote in the chimney if it has not been cleaned properly or regularly.
    • Never burn garbage, plastic, particleboard, plywood, salted driftwood or painted or treated wood.  Toxic chemicals are released which are harmful to human health.


What if my fireplace emits smoke?

    • Remember, smoke means air pollution. If you see or smell smoke in your house, it usually means your fireplace system isn't venting properly. 
    • Your chimney must be inspected for blockages and to ensure the damper is working properly.
    • Proper ventilation is necessary to prevent deadly carbon monoxide poisoning. Keep the fire hot and small. Feed it regularly with split wood and never let it smoulder. A smouldering fire creates more smoke.
    • Don't overload your stove or fireplace. Air should move around inside for a cleaner burn.


What about animal nests in the chimney?

    • Birds and squirrels are the most common uninvited guests in urban residential areas because they have adapted well to urban environments. Depending on the region where you live many different types of animals take up temporary residence including owls, pigeons, woodpeckers and raccoons just to name a few.
    • Home owners should always check for animal nests before using the fireplace at the beginning of the burning season. A build up of creosote in a chimney where an animal has nested is a very serious situation that will spark a potential chimney fire very quickly if not first inspected for clear ventilation.
    • We recommend installing chimney caps to keep birds and animals out of chimneys.
    • Bird netting and/or bird-repellent spikes are humane ways to prevent birds from roosting on or in buildings.


Why are chimney nests such a serious hazard?

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    • Contrary to popular belief, squirrels do not hibernate over the winter. They breed twice per year, once in late winter / early spring and again in mid-summer. They are always actively looking for secure food resources and warm, safe lodging for their families.
    • To prevent animal infestations, open vents or holes in a chimney or roof should be repaired with 1.25cm (½") mesh hardware cloth or sheet metal that exceeds at least 15cm (6") beyond the hole. Check the area for loose roof vents, rotten or loose soffits, loose shingles and have them repaired professionally.
    • If the squirrel is above the damper, you can hang a 1.25cm (½") thick rope down the chimney. The squirrel will usually climb the rope and leave the chimney.
    • Toronto Animal Services has extensive information animal removal from chimneys at  If you wish to consult a professional, we recommend calling Peter Pekelny at ProPest at 416-487-4179.


Christmas Fireplace Safety

    • We have seen many unfortunate incidents over the years and must stress the importance of safety in the fireplace at Christmastime.
    • Never burn wrapping papers or boxes in the fireplace. A flash fire may result as wrappings ignite suddenly and burn intensely. This also produces excessive smoke which creates large build up of creosote inside chimneys.
    • Use care with "fire salts," which produce colored flames when thrown on wood fires. They contain heavy metals that can cause intense gastrointestinal irritation and vomiting if eaten. Keep them away from children.
    • Install both a smoke and carbon monoxide detector. Make sure the batteries work.
    • Keep a fire extinguisher on hand.
    • Make sure the area around the fireplace is clear of furniture, books, newspapers and other potentially flammable materials. Two feet away is a good rule.

  • Lighting the Fire
    • Clean out ashes from previous fires. Open the damper.
    • Use a fireplace grate.
    • Keep glass doors open during the fire.
    • Use fireplace tools to tend the fire.
    • Build a safe fire.
    • Always close the fire screen when in use.

  • Do’s & Don’ts
    • Never burn garbage, rolled newspapers, charcoal or plastic in the fireplace.
    • Never use gasoline or any liquid accelerant to help start a fire.
    • Keep small children and pets away from the fireplace.
    • Never leave a fire unattended.
    • Don’t close the damper until the embers have completely stopped burning.
    • Make sure the fire is completely out before going to bed or leaving the house.
    • When cleaning the fireplace, store ashes in a non-combustible container with a tightly fitting lid and place the container away from the house.
    • Never burn a Christmas tree in the fireplace.


Clean Air on Your Mind?

In the great outdoors, of course there's plenty of fresh air. But because we spend most of our time indoors surrounded by man-made objects like walls, furniture, paper, plastics, chemicals, food and dust we are exposed to more pollutants than we realize.

Many people are highly sensitive to chemical odours or ‘indoor air pollution’ and can suffer a variety of uncomfortable conditions, sometimes unaware of the cause or source.  Asthma rates are on the increase in adults and children and more and more people are developing allergies, even if they’ve never had them before.

While the exact cause of asthma is unknown, it appears to result from a complex interaction of predisposing factors (genetics), environmental factors that may sensitize the airways (such as cat and other animal dander, dust mites, cockroaches) and contributing factors (such as tobacco smoke, respiratory infections and indoor and outdoor air quality).

Avoiding or controlling “triggers” is important in managing asthma. In the home, where people spend a lot of time, you can reduce exposure to dust mites, molds and other contaminants.

Of course, keeping your chimney clean is very important, here are some other things you can do around the house to minimize unwanted health problems.

Vacuum instead of dusting

    • When you dust your house with a cloth you are only spreading dust around, not eliminating it. Remember to vacuum thoroughly in difficult to reach areas like under beds, sofas and chairs, draperies and wood moldings.
    • If you wish to vacuum small objects without getting them sucked inside the vacuum, place an old nylon over the nozzle.
    • Wrap pillows and mattresses in allergen-protective covers and regularly vacuum them. Place a pillow in a plastic garbage sealing the opening around the nozzle with an elastic. Let the vacuum suck as much air out of the bag as possible. When finished, open plastic bag and enjoy your freshened pillows.

Washing and Cleaning

    • When you wash your linens make sure the water is hot (130 degrees or above) to ensure dust mites and their eggs are eliminated.
    • Deep clean your carpets & floor surfaces once every season.
    • Purchase a high efficiency air cleaner to remove airborne pollutants.

Pets and Stuffed Animals

    • Try to avoid letting your pets sleep in the bedrooms.
    • Keep stuffed animals and busy shelves to a minimum as these are real dust-catcher locations. If you have lots of stuffed toys vacuum them frequently. 


    • Clean up spills as soon as they happen. Mould grows easily in damp or wet areas.
    • Keep humidity levels around 50% or less with a humidifier but make sure you frequently empty the unit to prevent the growth of mold in the tank.

Personal and Household Productsouse

    • Avoid wearing strong perfumes and aftershave lotions. Many people are sensitive, or even allergic to them.
    • Use paints, solvents and other household chemicals outside whenever possible.  Investigate alternatives at a natural products store in your neighborhood. 
    • Whiteout and magic markers release chemicals as well so use as seldom as possible and when they're not in use, put the lid on them.
    • Avoid using air fresheners. They only mask odours. Using one odour to mask another simply adds pollutants to the air.
    • Do not use pesticides. Use traps or baits and seal places where insects can enter your house.
    • Throw out harsh chemical cleaners and scented household cleaners. Use mild, unscented detergents for clothes and avoid fabric softeners.
    • Ensure that dry-cleaned clothes have no residual odours from the dry-cleaning solvents before you bring the clothes into your house.
    • Avoid using candles and oil lamps. They create particles (soot) that can be breathed.
    • Maintain your furnace filters regularly. Upgrade to at least pleated paper filters.
    • If you have an electronic air cleaner and you smell ozone, be aware that ozone is a respiratory irritant. Try washing the filter more often. If more frequent washing doesn’t get rid of the ozone smell, switch to a pleated paper filter.
    • Have your furnace serviced by a heating contractor.
    • If you find that the return air ducts are dirty, or if the ducts have not been cleaned since the house was built or you moved in, have your ducts cleaned. Ensure that the contractor does not spray chemicals, such as fungicides, disinfectants or essential oils, into the ducts. Note that CMHC research shows that you should not expect to improve your indoor air quality by having ducts cleaned.
    • When you replace your heating system, select a high-efficiency furnace.
    • Change bedding frequently and vacuum the mattress at the same time. Replace pillows once a year or more often.
    • Use as few carpets as possible in your house. Carpets are good dust collectors, as are soft furnishings in bedrooms.
    • Dust mites need humidity above 55 per cent to grow. Reducing the humidity in your house to less than 45 per cent helps prevent dust mites.

Reducing Chemical Contaminants

Contamination from common household chemicals can be a threat both to people with asthma and to people who do not have asthma.

    • Do not paint or renovate when the house is closed up. Use only new, low-odour paints and check that the paint is not spoiled before using.
    • Test paint before using it to make sure it does not leave a residual odour. See CMHC’s Building materials for the environmentally hypersensitive for information about paints.
    • Remove sources of chemical odours, such as perfumes and furniture made of particleboard, medium-density fibreboard, plywood or oriented strand board (OSB) from your bedroom.
    • Use hardwood furniture and flooring made of solid hardwood rather than pressed or laminated wood.
    • Do not store paints, lacquers and solvents inside your house.


    • Plants are a notorious source of mould. Keep them well ventilated and slightly underwatered in clean debris free trays.
    • Take care of your plants, and make sure there's a tray under them to catch any leaks from over watering. If your plant is sick, get professional advice. Do not treat it with chemicals.

What Is Carbon Monoxide?

Carbon monoxide (CO) as a colourless and odourless gas. Because you can't see, taste or smell it, it can affect you or your family before you even know it's there. Even at low levels of exposure, carbon monoxide can cause serious health problems. CO is harmful because it will rapidly accumulate in the blood, depleting the ability of blood to carry oxygen.

Where Does Carbon Monoxide Come From?

Carbon monoxide is a common by-product of the combustion (burning) of fossil fuels. Most fuel-burning equipment (natural gas, propane and oil), if properly installed and maintained, produces little CO. The by-products of combustion are usually safely vented to the outside. However, if anything disrupts the venting process (such as a bird's nest in the chimney) or results in a shortage of oxygen to the burner, CO production can quickly rise to dangerous levels.

The burning of wood, kerosene, coal and charcoal produce CO. Gasoline engines produce CO. CO production is at a maximum during the startup of a cold engine. Starting, then idling, your car or gas mower in the garage can be dangerous. The fumes that contain CO can enter a home through connecting walls or doorways and can quickly rise to dangerous levels.

How Can I Eliminate Sources of CO in My Home?

The most important step you can take to eliminate the possibility of CO poisoning is to ensure that CO never has an opportunity to enter your home. This is your first line of defense. Review this list to minimize the risk of CO in your home.

    • Don’t idle your car in your attached garage. To minimize contaminants from vehicle exhaust from getting into your house, seal all apparent leaks on the wall between the garage and the house. Keep the garage doors open after you put your car in the garage or do not use the door between your garage and the house.
    • Have a qualified technician inspect and clean fuel-burning appliances yearly, before the cold weather sets in, to ensure they are in good working order.
    • Have a qualified technician inspect chimneys and vents yearly for cracks, blockages (e.g., bird's nests, twigs, old mortar), corrosion or holes.
    • Check fireplaces for closed or blocked flues.
    • Check with a qualified technician before enclosing heating and hot water equipment in a smaller room, to ensure there is adequate air for proper combustion.
    • If you have a powerful kitchen exhaust fan or downdraft cooktop, have a qualified technician check that its operation does not pull fumes back down the chimney.
    • Never use propane or natural gas stove tops or ovens to heat your home.
    • Never start a vehicle in a closed garage; open the garage doors first. Pull the car out immediately onto the driveway, then close the garage door to prevent exhaust fumes from being drawn into the house.
    • Do not use a remote automobile starter when the car is in the garage; even if the garage doors are open.
    • Never operate propane, natural gas or charcoal barbecue grills indoors or in an attached garage.
    • Avoid the use of a kerosene space heater indoors or in a garage. If its use is unavoidable provide combustion air by opening a window while operating. Refuel outside after the unit has cooled.
    • Never run a lawnmower, snowblower, or any gasoline-powered tool such as a whipper-snipper or pressure washer inside a garage or house.
    • The use of fossil fuels for refrigeration, cooking, heat, and light inside tents, trailers, and motorhomes can be very dangerous. Be sure that all equipment is properly vented to the outside and use electric or battery-powered equipment where possible.
    • Regularly clean the clothes dryer ductwork and outside vent cover for blockages such as lint, snow, or overgrown outdoor plants.
    • Reduce or eliminate the use of fondue heaters indoors.
If you live close to a road with heavy traffic, outdoor carbon monoxide levels can affect your indoor air quality, especially during rush hour. Such levels should not set off a CO alarm, but slightly elevated CO levels might be observable on some types of CO detectors with a digital display.