How to Season Firewood in Canada

Seasoning — the process of reducing moisture content in cut wood — determines how well firewood performs when burned. In Canada, where winters are long and heating demands are real, wood that hasn't dried properly puts more energy into evaporating water than into heating a room.

The standard target for firewood moisture content is below 20%, measured with a moisture meter in the centre of a freshly split piece. Above that threshold, combustion is incomplete, smoke output increases, and creosote accumulates in flues and chimneys — a fire hazard that Natural Resources Canada notes as a common cause of chimney fires in wood-heated homes.

When to Split and Stack

The best time to start seasoning firewood is as early in spring as possible after the snow clears — typically March to May depending on province. Wood split in April gives six months of drying before the heating season begins in October, which is enough for most softwoods and faster-drying hardwoods like aspen and birch.

Splitting accelerates drying significantly. A round log loses moisture primarily through the cut ends; a split log exposes far more surface area to air. For dense species like Manitoba maple or white oak, splitting to pieces no wider than 10–15 cm across the face gives the best results within a single season.

Regional Note

In British Columbia's Interior and across much of the Prairies, the combination of low humidity and strong seasonal winds means hardwoods like birch can reach burnable moisture levels in six to eight months. In the humid Maritime provinces and parts of Ontario, the same species may need twelve months or more in an outdoor stack. Covering the top while keeping sides open is especially important in wetter regions.

Drying Times by Species

The figures below are general ranges observed under typical Canadian outdoor stacking conditions — a covered stack with open sides, elevated off the ground, in a location with some wind exposure. Actual results vary by location, stack density, piece size, and the specific year's weather.

Species	Green Moisture (approx.)	Drying Time
Trembling Aspen	~95–100%	6–9 months
White Birch	~60–80%	6–12 months
Green Ash	~45–55%	10–14 months
Manitoba Maple	~55–65%	12–18 months
Eastern White Oak	~80–90%	18–24 months
Jack Pine	~90–100%	3–6 months
Black Spruce	~85–95%	4–7 months

Stacking for Airflow

Moisture leaves wood through the cut ends and the exposed grain. A stack that allows air to move through it dries faster than a dense pile where pieces are packed tightly. Row stacking — with consistent gaps of 2–3 cm between pieces — is the most reliable method for achieving this.

Orient the stack so its length runs across the prevailing wind direction. In most of southern Canada, prevailing winds come from the west or northwest for much of the year, meaning a stack oriented north-south catches the most airflow through its layers.

Stack Height and Stability

Standard advice puts the practical maximum height for a freestanding row stack at about 1.5 to 1.8 metres without end supports, and up to 2 metres with solid end posts or a crib construction at the ends. Taller stacks in exposed locations are susceptible to toppling during wind or when the ground shifts during spring thaw.

What to Avoid

Stacking directly on bare soil — the bottom row absorbs ground moisture and rots faster
Covering the sides of the stack — this traps humid air and slows drying, or reverses it in wet periods
Stacking against a house wall — this brings insects and moisture into close contact with the structure
Mixing green and seasoned wood in the same stack — dry wood can absorb moisture from green pieces when stacked in contact

Checking if Wood is Ready

A moisture meter is the most reliable method. Insert the probes into a freshly split face, away from the ends, for an accurate reading. Visual and tactile indicators — grey-brown colouring on the cut face, cracks radiating from the centre, a hollow sound when two pieces are struck together — suggest dryness but are not precise.

The Ontario government's wood heating guidance recommends burning only seasoned wood with moisture content below 20% in certified wood stoves, as a measure to reduce particulate emissions and chimney maintenance requirements.