If you plan to use a wood stove to help heat your home this winter, use extreme caution. According to the National Fire Protection Association (NFPA), supplemental heating equipment, such as a wood stove, is the leading cause of home fires during the months of December, January and February. Home heating equipment trails only cooking equipment as the leading cause of home fires year-round.
How to Select a Wood Stove
Here are some things to look for when selecting a wood stove:
- Be sure your wood stove is made of sturdy, suitable material, such as cast iron or steel.
- Look for stoves with the Underwriters Laboratories (UL) label.
- If you purchase a used stove, check it carefully for cracks or other defects. The legs, hinges, grates and draft louvers should also be checked carefully.
Wood Stove Codes and Installation
In most areas, new installation of wood stoves must meet local building codes. In addition, the NFPA provides the standard for chimneys, fireplaces, vents and solid fuel-burning appliances (NFPA 211).
All operating wood stoves and furnaces require specific minimum distances or clearances between the bottom, top, sides, front and back of the stove and any combustible materials, such as floors, walls, ceilings, curtains and furniture.
Insufficient clearance could cause heat produced by the stove to penetrate into nearby combustibles, causing a serious fire.
The recommended clearances are found in the NFPA 211, your local building codes and your wood stove's operator's manual.
Venting the Stove
Venting the stove is a very important part of the wood burning stove system since 90 percent of all stove related fires originate within the venting system.
A venting system is not a chimney. It consists of lengths of 24 gauge or heavier stovepipe, which must be as short as possible with no more than two right angle elbows. The sections of stovepipe should be assembled with crimped, male ends of the sections facing down, toward the stove. Stovepipe sections should be fastened with at least three sheet-metal screws or other fasteners. The stovepipe seams must overlap and face up on inclined runs.
Stovepipe clearances are extremely important. The stovepipe must never pass through an interior wall, floor or ceiling. A stovepipe should never be used for a chimney because the elements will cause it to rust.
Where possible, the stovepipe must go directly into a lined masonry or UL listed, factory built chimney. If the stovepipe must pass through an exterior wall to reach the chimney, maintain at least 18 inches of clearance to all combustibles. Consult fire codes and use metal thimbles made for this purpose.
Wood Stove Chimneys
The chimney for a wood stove must be masonry or metal that is UL listed and factory built.
An unlined single brick chimney should never be used for a wood stove! Single brick chimneys are prone to deterioration, which may allow potentially dangerous situations to develop. Many older homes have an unlined chimney constructed of double brick. An unlined double brick chimney may be used for a wood stove after carefully checking for cracked mortar or loose or missing brick.
Metal sleeves listed by the UL may be used as chimney liners only if they were designed for such use.
Factory built, metal chimneys must never be used with a coal stove, as the corrosive flue gases produced by a coal fire will cause rapid deterioration.
Metal chimneys should be completely disassembled after a chimney fire and checked for damage. Discoloration of the exterior indicates a possible breakdown of the insulating material. Any questionable section should be replaced.
Each wood stove should have its own flue within the chimney and should not be connected to the same flue as any other heating appliance.
Wood Stove Dampers
If a wood burning stove has an automatic draft regulator controlled by a thermostat, the manufacturer's instructions for installing it must be carefully followed.
A manually operated damper can be installed on the pipe near the stove. This damper should not obstruct more than 80 percent of the pipe area.
A second damper higher up on the vertical section of the stovepipe is advisable to permit shutting down the stove in case of a chimney fire.
Wood Stove Safety Tips
Some tips to safely use your wood stove, include:
- Make sure there is enough clearance between the wood stove and combustible materials, including floors, walls and ceilings.
- Place the wood stove on a noncombustible, fire resistant base.
- Have a mason or other qualified person inspect the chimney.
- Burn only dry, well-seasoned wood.
- Consider opening or cracking a window for ventilation.
- Dispose of ashes in a closed metal container outside and away from the house.
What Not to Do
If you have a wood burning stove, you should never:
- Extend the stovepipe through a wall or ceiling unless there is no possible alternative.
- Connect a wood stove to a fireplace chimney unless the fireplace has been sealed off.
- Connect a wood stove to a chimney serving another appliance burning other fuels.
- Start a wood stove fire with flammable fluids, such as gasoline.
- Burn trash in a wood stove; doing so can start a chimney fire.
- Let a wood fire burn unattended or overnight.