Seasoned vs Green Firewood: Why It Matters
Seasoned wood has been dried to under 20% moisture. Green wood is freshly cut and can be over 50% water by weight. That difference decides how much heat you get, how much smoke you make, and how fast your chimney clogs.
Green wood is usually cheaper. It is rarely the better buy, and it is sometimes sold as seasoned by people who have not checked.
What burning wet wood actually costs you
- Heat goes into boiling water, not into the room. A substantial share of the energy in green wood is spent evaporating its own moisture before it can warm anything.
- Creosote. Cool, smoky, incomplete combustion deposits tar in the flue, and creosote is what chimney fires are made of. This is the reason that matters.
- It is unpleasant to burn. Hissing, spitting, hard to light, hard to keep going, and a glass door that blacks over in an evening.
- Smoke. More of it, and in some areas that is a neighbourhood and regulatory problem as well as a nuisance.
How to tell, at the pile
Four checks, none of which need a meter:
- Cracks in the end grain. Seasoned logs split radially from the centre as they dry. A smooth, uncracked end face is a wet log.
- Weight. Pick two similar pieces up. Dry wood is startlingly lighter than it looks.
- Sound. Knock two logs together. Seasoned wood gives a sharp crack; green wood gives a dull thud.
- Bark and colour. Seasoned wood is greyed and its bark often loosens or falls off. Bright, tight bark and pale fresh-cut faces mean recent.
A moisture meter costs very little and settles it in seconds: split a log and test the freshly exposed inside face, not the outside, which always reads drier. Under 20% is ready.
How long seasoning takes
| Species | Time to season |
|---|---|
| Ash | 6–12 months — the fastest, and burns acceptably even slightly green |
| Birch, softwoods | 6–12 months |
| Maple, cherry | 12 months |
| Oak | 12–24 months — famously slow, and worth the wait |
| Elm | 24 months, and still awkward |
"Seasoned" is not a regulated term. Plenty of wood is sold as seasoned at three months, which for oak is nowhere near enough.
Buying green on purpose
There is one good reason to: price and planning. Green wood is noticeably cheaper, and if you buy it in spring and stack it properly, it is seasoned by the time you need it. That is the cheapest way to heat with wood, and it is what most people who burn seriously actually do.
It only works if you have somewhere to put it for a season, and if you are buying oak, that season needs to be two.
Stacking it so it dries
- Off the ground. Pallets, rails, anything. Ground contact wicks moisture straight back in.
- Top covered, sides open. This is the one people get wrong. A tarp over the whole stack traps moisture and the wood stays wet — cover the top third and leave the ends and sides to the wind.
- Sun and wind, not shelter. Airflow dries wood; a still corner of a garage does not.
- Split first. Bark is waterproof by design. Rounds left unsplit barely season at all.
- One row deep where you can, with gaps.
What to ask before you buy
"Is it seasoned?" gets a yes from everyone. These get real answers:
- "When was it cut?" A date is checkable; an adjective is not.
- "What species?" It sets the seasoning time — see which firewood burns best.
- "Has it been split and stacked, or is it in rounds?" Unsplit rounds have not been seasoning, whatever the date.
- "Can I see it?" Thirty seconds of end grain tells you more than any answer.
Then work out how much you need — how much is a cord of wood has the arithmetic and the face-cord trap. Find suppliers near you on Topsoil.com.