Why does my fireplace smoke

That said, if you are constructing a chimney, we always recommend consulting a professional as well as checking local building code. A throat or smoke chamber that is too tight for the size firebox will create smoke draw issues.

The throat front and back should fit well at the top of the firebox and not restrict the opening air space. If you have a throat damper, ensure it does not restrict the throat opening either. Check to see if firebrick or other material has been added to the back of the throat, which would reduce the throat opening area and should be removed.

Feel around for smooth, streamlined surfaces with no obstructions that would restrict or redirect air flow. For a fireplace to draw well, you need to be sure the flue size is adequate for the amount of smoke that can be created in the firebox. A good rule of thumb is that the fireplace opening be no more than x the area of the flue. A smaller flue simply can't process the amount of smoke, causing some to spill back into your home.

Flue size should be matched to firebox size in accordance with Section R And remember, bigger is not always better. Your flue should be the appropriate size for your fireplace.

If a flue is too large, the amount of heat produced by a small fire might not be enough to drive the draft upward. A house that has multiple flues sharing one chimney chase may transfer smoke to one another when one is burning and the other is not, causing smoke to reenter the home. When you light a fire in one fireplace, you are creating a negative pressure inside the house.

If the house is fairly airtight then the easiest way for the fire to get air is through the open flue of the other fireplace —in other words the smoke goes up the chimney and gets sucked back down the other flue along with the necessary fresh air.

To fix this, you can extend the height of the flue that is causing the smoking to make one flue higher than the other. This allows the smoke to escape without getting pulled back down with the fresh air.

If adding height to the chimney is not an option, you can also consider adding an outside air kit also called a fresh air kit to the fireplace that is causing the smoking. Smoke spillage can be caused by a variety of different factors, some of which are easier to fix than others.

The most common causes of smoke entering the home are:. However, this list is not exhaustive of all possible scenarios, nor can it be — other potential influences include:. Closed Damper The most likely reason that your house is filling with smoke when you light a fire is that the damper is closed.

Throat Damper The majority of dampers are cast iron throat dampers. Top Seal Damper The other type of damper you could have is a top seal damper. Creosote Build Up If you have a wood burning fireplace, one of the most common and most dangerous chimney blockages is creosote.

Bird Nests and Animal Blockages Critters, such as squirrels, birds, and bats, have been known to make their homes in chimneys. Pressure Differential A well-functioning house will have close to neutral indoor air pressure and will work to keep the pressure natural. Adequate Airflow Modern houses tend to be very tight think spray foam insulation, house wrap, weather-sealed windows, etc.

Rain or snow can easily seep into an uncovered flue. Once there, the water will lower the temperature of the air in the firebox and impede its ability to rise, weakening the draft to potentially cause back-puffing.

If the fireplace seems to kick back smoke only when or after it rains or snows, you may have a water seepage issue. This covering installed around the outside opening of the flue keeps out water along with animal nests and debris to help strengthen the chimney draft and prevent indoor smoke. A flue can become blocked by leaf debris, animal nests, or the buildup of creosote, a dark brown to a black coating that forms in the chimney when fire by-products harden.

These obstructions can reduce or prevent the passage of smoke from the firebox to the outdoors through the flue and lead to back-puffing.

Far more seriously, when the temperature in the flue is high enough, creosote build-up or debris can ignite a chimney fire that can do serious structural damage to your home. Uncovering dark buildup when you scratch a finger against your chimney walls is a telltale sign of creosote buildup while observing nests or debris when you put a flashlight up your chimney flue can tip you off to a larger obstruction in the flue.

If you spot either, call a CSIA-certified chimney sweep to inspect the chimney and, if needed, clean it to remove creosote buildup, nests, and other debris and keep back-puffing at bay.

A strong chimney draft requires neutral air pressure—that is, outside air enters the home at the same rate that inside air exits it, so that indoor and outdoor air pressure is the same. When a fire is built using the top-down method the fire is started at the top. Any smoke initially generated by the fire is located further towards the top of the fireplace, further reducing the potential for smoke to come out of the fireplace.

With no logs on top in a top-down fire, the fire can provide a much cleaner and more efficient burn right from starting the fire. By building top-down fires in your open fireplace you can help to reduce the amount of smoke that is produced at the start of the fire , as well as helping to minimize the amount of smoke that can come out of your fireplace through lighting the fire more towards the top of the fireplace.

The bark on dry wood can also be coming off more easily than on wet wood. A moisture meter is an essential tool for any fireplace. A fire may not be able to properly combust wood and can produce more smoke if there is also a lack of sufficient airflow to the fire.

To help ensure that the draft is working as efficiently as possible so that air can be continuously fed to the fire, fully open the damper in your fireplace before each and every fire.

It your fireplace has a damper it will typically be located within the top area of your fireplace. Dampers can be closed between fires to help prevent heat loss from a home, but must be opened prior to each fire to ensure that all waste gases and smoke can be safely vented from a home. To further help reduce the potential for smoke to be produced by as much as possible, warming up the air within the chimney before starting a fire can help to start the draft on your fireplace.

A strong draft is essential for maintaining the continuous cycle of waste gases and smoke being removed from your home, while also sucking fresh air into a fire from the room. To help start the draft we always warm up our chimney before each fire. We take a single sheet of newspaper, roll it up and light it at one end.

We then place the newspaper under the chimney inside the top of our fireplace and leave it to burn for a short while. You can find out more ways to help warm a chimney in another one of our articles here. Heavy smoke inhalation can cause serious health problems, such as:. Along with these dangers of inhaling fine particles, wood smoke also contains toxic and harmful air pollutants, such as carbon monoxide CO , benzene, formaldehyde, acrolein, and polycyclic aromatic hydrocarbons PAHs.

Without proper drafting and ventilation, these pollutants can harm your health. You should address your smoky fireplace as soon as possible and install a CO detector in your home to warn you when CO levels increase. You should clean your chimney at least once a year, and more often if you use your fireplace heavily.

The presence of soot and creosote can fuel a chimney fire that at the very least, could damage your chimney, and at worst, spread to your roof and home. Plan to clean and inspect your chimney before the start of the burning season. This will ensure your fireplace is clean, safe, and drafting properly.

To keep your fireplace clean, functioning efficiently, and looking great, clean it regularly. But make sure that all embers have been extinguished for at least 12 hours before cleaning your fireplace. And never use cleaners that are toxic or flammable.