What “unseasoned” means
Unseasoned (or “green”) wood is timber that has been recently felled or cut. It still contains a high proportion of moisture — typically 40–60% by weight in hardwoods and even more in softwoods. Burning green wood is inefficient: it produces excessive smoke, creates creosote build-up in flues, and delivers far less heat than dry wood.
Ready-to-burn wood
“Ready to burn” means the moisture content has dropped below 20%, which is the threshold at which wood burns cleanly and efficiently. In the UK, DEFRA's Ready to Burn scheme certifies commercially sold logs at this standard. Free firewood almost never comes with a moisture certificate — seasoning is your responsibility.
How long does seasoning take?
As a rough guide for UK conditions:
- Softwoods (pine, spruce, larch): 6–12 months.
- Medium hardwoods (birch, willow, poplar): 12–18 months.
- Dense hardwoods (oak, ash, beech): 18–24 months, sometimes longer for thick rounds.
Splitting logs accelerates drying dramatically. A round 30 cm log can take twice as long as the same wood split into quarters. Stack wood off the ground with good airflow and top cover (but open sides) for best results.
Why most free logs are unseasoned
Free firewood typically comes from tree surgery, storm clearance, or garden work — all of which produce freshly cut wood. Tree surgeons in particular want timber removed quickly to clear the site and avoid disposal costs. They rarely have space or reason to season logs before giving them away.
This is why free firewood is best thought of as a long-term fuel supply: collect now, season over summer, burn next winter (or the one after for very dense hardwoods).
How to tell if wood is seasoned
- Colour is duller and greyer than freshly cut wood.
- End grain shows visible cracks (checking).
- Logs feel lighter than expected and sound hollow when knocked together.
- A moisture meter reads below 20% (inexpensive meters are widely available).
What to do with free unseasoned logs
- Collect and transport — bring a vehicle and gloves. Most listings are already cut to liftable pieces. If the wood is still in long lengths and the giver is happy for you to cross-cut on site, bring a saw — but this is optional, not the default.
- Split promptly — splitting green wood is easier than seasoned and speeds up drying.
- Stack in a ventilated store — off the ground, covered on top, open sides.
- Wait — check moisture with a meter before burning.
Find free logs near you
Browse live listings on Firewood Friends or install the app to get alerts when free wood appears in your area.
