Atlanta Chimney Sweep
What causes chimney fires?
Chimney fires are usually caused by the accumulation of creosote in the chimney. Creosote is a natural by-product of burning wood. It accumulates in the flue over time and is highly flammable. Creosote is especially likely to accumulate when wood is not burned at the proper temperature. Since creosote is flammable, when it accumulates on the walls of your flue, hot flue gasses can ignite it. The result is a chimney fire. Depending on the condition of your chimney, such a fire can pose a significant threat to the rest of your house. Flames from the fire can find their way through cracks in your clay chimney liner or mortar and ignite framing around the chimney. They can also spill over onto the roof and cause a fire there.chimney, such a fire can pose a significant threat to the rest of your house. Flames from the fire can
How Chimney Fires Hurt Chimneys?
Masonry Chimneys. When chimney fires occur in masonry chimneys – whether the flues are an older, unlined type or are tile lined to meet current safety codes – the high temperatures at which they burn (around 2000°F) can "melt mortar, crack tiles, cause liners to collapse and damage the outer masonry material". Most often, tiles crack and mortar is displaced, which provides a pathway for flames to reach the combustible wood frame of the house. One chimney fire may not harm a home. A second can burn it down. Pre-fabricated, factory-built, metal chimneys. To be installed in most jurisdictions in the United States, factory built, metal chimneys that are designed to vent wood burning stoves or pre-fabricated metal fireplaces must pass special tests determined by Underwriter`s Laboratories (UL). Most tests require the chimney to withstand flue temperatures up to 2100°F – without sustaining damage. Under chimney fire conditions, damage to these systems still may occur. When pre-fabricated, factory-built metal chimneys are damaged by a chimney fire, they should no longer be used and must be replaced.
Ways to Keep the Fire You Want...from Starting One You Don’t!
Chimney fires don’t have to happen. Here are some ways to avoid them. . Use seasoned woods only (dryness is more important than hard wood versus soft wood considerations . Build smaller, hotter fires that burn more completely and produce less smoke . Never burn cardboard boxes, wrapping paper, trash or Christmas trees; these can spark a chimney fire . Install stovepipe thermometers to help monitor flue temperatures where wood stoves are in use, so you can adjust burning practices as needed . Inspect and clean catalytic combustors on a regular basis, where applicable
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 cleaning 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.
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.
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.
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.
Short Menu
- What causes chimney fires?
- How Chimney Fires Hurt Chimneys?
- Ways to Keep the Fire You Want
- My fireplace stinks...
- I get smoke from the basement fireplace...
- I heat with gas. Should this chimney be checked too?
- How common is it that chimney liners cannot be seen from inside the fireplace using only a flashlight?