Chimney Cricket’s Chimney and Fireplace Safety Tips

Imagine yourself cuddled up in front of a cozy, warm fire on a snowy night. In all likelihood, the last thing on your mind is the condition of your chimney. Unfortunately, if you don't give some thought to it before lighting those winter fires, your enjoyment may be very short-lived.

Dirty chimneys can cause chimney fires. These can either be slow-burning, keeping them invisible to bystanders, or they can be explosive – dramatic and highly visible to everyone around. Those that are explosive can destroy homes and injure or kill people, while both types cause severe structural damage. Whether you are investing in a new home with a fireplace and/or chimney or are interested in learning more about your current one, the professionals at Chimney Cricket are eager to help!

What Is Creosote?

Fireplaces and wood stoves are designed to safely contain wood-fueled fires, while providing heat for a home. The chimneys that serve them have the job of expelling the by-products of combustion - the substances given off when wood burns. As these substances exit the fireplace or wood stove, and flow up into the relatively cooler chimney, condensation occurs. The resulting residue that sticks to the inner walls of the chimney is called creosote.

Creosote is black or brown in appearance. It can be crusty and flaky ... tar-like, drippy and sticky ... or shiny and hardened. Often, all forms will occur in one chimney system. Whatever form it takes, creosote is highly combustible. If it builds up in sufficient quantities - and catches fire inside the chimney flue- the result will be a chimney fire.

Although any amount of creosote can burn, sweeps are concerned when creosote builds up in sufficient quantities to sustain a long, hot, destructive chimney fire.

What Conditions Cause Chimney Fires?

Certain conditions encourage the buildup of creosote, restricted air supply, unseasoned wood and cooler-than-normal chimney temperatures are all factors that can accelerate the buildup of creosote on chimney flue walls.

Air Supply

The air supply on fireplaces may be restricted by closed glass doors or by failure to open the damper wide enough to move heated smoke up the chimney rapidly (the longer the smoke's "residence time" in the flue, the more likely is it that creosote will form). A wood stove's air supply can be limited by closing down the stove damper or air inlets too soon and too much, and by improperly using the stovepipe damper to restrict air movement.

Burning Unseasoned Firewood

Because so much energy is used initially just to drive off the water trapped in the cells of the logs - burning green wood keeps the resulting smoke cooler, as it moves through the system, than if dried, seasoned wood is used. Burning seasoned hardwoods will greatly reduce your risk of a chimney fire and help reduce creosote build-up.

Cool Flue Temperatures

Cool flue temperatures speed creosote production, too. Condensation of the unburned byproducts of combustion occurs more rapidly in an exterior chimney, for example, than in a chimney that runs through the center of a house and exposes only the upper reaches of the flue to the elements.

How Chimney Fires Damage 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.

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.

Wood Stoves

Wood stoves are made to contain hot fires. The connector pipes that run from the stove to the chimney are another matter. They cannot withstand the high temperatures produced during a chimney fire and can warp, buckle and even separate from the vibrations created by air turbulence during a fire. If damaged by a chimney fire, they must be replaced.

Ways To Avoid Chimney Fires

• Use seasoned woods only (dryness is more important than hard wood versus soft wood considerations)
• Build smaller, hotter fires that bum 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
• Have the chimney inspected and cleaned on a regular basis

Proper Chimney And Fireplace Maintenance

Clean chimneys don't catch fire. Make sure a Chimney Cricket expert inspects your solid fuel venting system annually, and cleans and repairs it whenever needed. Our sweep may have other maintenance recommendations depending on how you use your fireplace or stove. Below are more tips for chimney and fireplace maintenance.

When To Have Your Chimney Cleaned and Inspected?

The National Fire Protection Association (NFPA 211) advises at least annual chimney check-ups and cleanings. If you use your chimney often, you will want to clean it more often. The best time to have Chimney Cricket inspect and clean your chimney is in the spring. Chimney sweeps are less busy during this time, as opposed to the fall season.

How To Avoid A Smelly Fireplace

Smells emitting from a fireplace are normally caused by rain, moisture, and high humidity. If you have the chimney cleaned in the early spring, it will be prepared for the high humidity of the summer months. You can also have a sealing damper installed to prevent smells.

Chimney Caps

The chimney cap is an easy way to keep your chimney maintained. By placing a chimney cover or cap on your flue, you will keep moisture, animals, debris and other hazards out of the chimney. Make sure you have a durable and quality chimney cap installed to withstand the outside elements.

Storms Can Damage Your Chimney

Proper chimney maintenance includes having both the exterior and interior inspected for damage after a violent storm or natural disaster. Make sure you do not use the fireplace before you have it inspected. The professionals at Chimney Cricket are certified and able to spot and fix problems in your chimney.

Signs That You’ve Had A Chimney Fire

Since chimney fires can occur without anyone being aware of them…and since damage from such fires can endanger a home and its occupants, how do you tell if you’ve experienced a chimney fire? Here are the signs a professional chimney sweep looks for:

• "Puffy" creosote, with rainbow colored streaks, that has expanded beyond creosote’s normal form
• Warped metal of the damper, metal smoke chamber connector pipe or factory-built metal chimney
• Cracked or collapsed flue tiles, or tiles with large chunks missing *Discolored and/or distorted rain cap
• Heat-damaged TV antenna attached to the chimney
• Creosote flakes and pieces found on the roof or ground
• Roofing material damaged from hot creosote
• Cracks in exterior masonry
• Evidence of smoke escaping through mortar joints of masonry or tile liners

If you think a chimney fire has occurred, call Chimney Cricket for a professional evaluation. If your suspicions are confirmed, a certified sweep will be able to make recommendations about how to bring the system back into compliance with safety standards. Each situation is unique and will dictate its own solution.

What To Do If You Have A Chimney Fire

If you realize a chimney fire is occurring, follow these steps: *Get everyone out of the house, including yourself *Call the fire department These additional steps may help save your home. Remember, however, that homes are replaceable, lives are not:

• Put a chimney fire extinguisher into the fireplace or wood stove
• Close the glass doors on the fireplace
• Close the inlets on the wood stove
• Use a garden hose to spray down the roof (not the chimney) so the fire won’t spread to the rest of the structure.
• Monitor the exterior chimney temperature throughout the house for at least 2 to 3 hours after the fire is out.

Protect Your Family

Installing a carbon monoxide detector in your home is a smart idea. It will warn you about harmful gases that can be entering your home if your chimney is damaged. These gases may not always be noticed by humans, making a detector an important investment.

Call Chimney Cricket For Service!

We are able to help you with all your fireplace and chimney maintenance needs. Don’t hesitate to call today.