Burning wood safely

In order to maximize safety and to derive the most benefit from any solid fuel-heating appliance, burn only well-seasoned, clean and untreated wood. Scraps of wood, especially those from residential use, may have been treated with chemicals that can damage the stove and create an unhealthy environment in the home.

Freshly cut wood is not a good choice either, since it is damp, difficult to ignite, does not properly sustain combustion and creates excessive amounts of creosote. As a general rule, wood properly stacked and stored in the spring will be ready to burn by fall, however optimum value and performance is usually gained through seasoning the wood for a year.

Creosote

Creosote is an oily fluid released from wood tar during the burning process and occurs as a result of incomplete combustion. Tar droplets, composed mainly of hydrogen and carbon, are formed through a number of conditions, such as inadequate temperatures for proper burning, insufficient oxygen, improper venting or incorrect flue sizing. You can reduce creosote buildup through efficient burning of properly seasoned fuel.

Temperature has a major impact on the rate of creosote buildup. The cold of the Canadian winter is a major influence on this. For added safety, and to reduce the potential for a serious creosote buildup, chimneys should be installed inside the home and meet ULC Standard S629M.

Other factors that may cause rapid creosote buildup are over-sized appliances, slow fires, insulation breakdown in the appliance and cool chimneys.

Creosote causes chimney fires

Creosote is flammable and, if ignited, can cause loss of life and property. Creosote deposits as small as 0.3 cm (1/8 inches) can cause a chimney fire. Under the stress of a chimney fire, chimneys not meeting ULC Standrad S629M may fail, causing loss of property. Chimney fires burn at temperatures exceeding 1147 C (2100 F).

The smell of burning tar, a roaring sound coming from the flue pipe or chimney and sparks or flame coming from the chimney, are signs a serious creosote fire may be in progress. Immediately evacuate the home and contact the fire department.
Note: Only chimneys meeting ULC Standard S629M are designed to contain the heat and destructive force of such temperatures.

To prevent dangerous chimney fires, a qualified professional should check the stove, vent pipes and chimney regularly (at least every two weeks at the start of the burning season until a pattern is established).

Proper installation

Solid fuel heating appliances should always be installed by qualified professionals who hold certificates indicating their training and expertise. All component parts, including stove and chimney, should be sold and installed as a unit. Devices such as fireplace inserts, masonry fireplaces and pre-fabricated metal fireplaces are also specialized appliances and should be installed professionally for your safety.

Safe operation of a wood burning stove

A professional should verify proper sizing of your heating unit. Retain the manufacturers’ instruction manuals and rely on them to ensure safe operation of the unit.

Follow the manufacturer’s guidelines for the proper burning of wood in your stove. As a general guide, the following may be noted:

Cold start:

The objective is to quickly establish a hot, clean burning fire.
The fire should be started using an adequate amount of crumpled newspaper and an adequate amount of finely split wood (kindling) arranged in a criss-cross pattern to prevent collapse and smothering as the crumpled newspaper burns.
The kindling load should be sufficient to pre-heat the chimney and the stove’s internal surfaces.
When the kindling is flaming, larger kindling may be added to the fire.
Once the larger kindling has charred and a stable fire has been established, add firewood leaving the combustion air controls open until the stove reaches its operating temperature.

Hot start:

Live coals from an overnight fire will usually be available in the stove in the morning.
Rake the live coals so they are near the combustion air inlets. If the stove is equipped with combustion air wash for the glass door, rake the live coals to the front of the firebox near the door.
Place fresh wood behind and on top of the coals, taking care not to smother the coals.
Leave the combustion air controls open until the stove reaches its operating temperature.

Note: It may be necessary to use newspaper and kindling if only a small number of coals remain.