The Importance of Dry, Kiln Dried Firewood
"Dry" is one of the most misused words in firewood. A log that's been left in a shed for a few months might appear dry on the outside, but that doesn't mean it's dry on the inside and ready to burn. Moisture content is the one of the biggest factors in how well your fire performs, so it is important to actually check what you're burning.
Why Moisture Content Matters
- Wet wood wastes energy - Instead of heating your room, the fire is burning off water first and produces little heat
- More smoke, more soot - Unburnt moisture creates the thick smoke that coats your flue and windows
- Higher risk of chimney fires - Smokey, inefficient burns build up creosote faster
- Harder to light and keep going - You'll use more firelighters and kindling for a poor burning result
How To Tell If Your Firewood Is Actually Dry
Use a moisture meter This is the only true way to actually know if your firewood is dry for certain. Push the probes into a freshly split log (test the inside, not the weathered outer surface) and take a reading. This removes all the guesswork the tricks below rely on.
Some alternative (but not fool proof) methods to check your firewood:
Look at the ends - Dry logs typically show cracks or "checking" radiating out from the centre, like the spokes of a wheel. Wet firewood tends to look solid and unmarked at the cut ends.
Check the colour - Freshly cut wood is often pale and slightly damp looking. Kiln dried wood tends to be a duller, more faded shade of its natural colour.
Do the knock test - Bang two logs together. Dry firewood makes a sharp, hollow "clack." Wet wood gives a dull, heavy thud.
Feel the weight - Pick up two similarly sized logs. Wet wood is noticeably heavier, since it's still carrying its water content.
Peel the bark - Bark on dry logs is often loose and comes away easily. On wet wood, it tends to cling on tightly.
What The Numbers Should Say
Under the Government's Ready to Burn scheme, firewood must have a moisture content below 20% to be sold as ready to burn. That is the legal minimum standard.
At Well Seasoned Wood, our kiln dried firewood is guaranteed below 15% moisture, and typically sit at 8–10%. That's well under the Woodsure Ready to Burn threshold, which means a hotter, cleaner burn with less smoke and far less strain on your chimney, right out of the bag.
Kiln Dried vs. "Seasoned" vs. The Bag From The Garage
Not all firewood sold as "dry" is equal:
- Kiln dried firewood has been through a controlled drying process to bring moisture content down consistently and reliably, batch after batch. That's the only way to guarantee the low numbers above.
- Seasoned firewood has simply been left to dry naturally, usually outdoors under cover. Depending on how long it's been stored and how well, moisture content can vary hugely - anywhere from acceptable to well over 30%.
- Supermarket, garage, and petrol station nets are legally required to meet the same 20% Ready to Burn threshold as anyone else selling firewood in small volumes. But 20% is a ceiling, not a target, and there's no way to check the actual reading on a sealed bag at the till. A net that scrapes in just under the legal limit is a very different fire to one guaranteed at 8–12%.
What You're Actually Paying For
It's tempting to assume the bag from the garage is the cheaper option. Usually, it isn't. Our nets are £8.75 or less, and give you 10–12kg of wood. A comparable net from a major supermarket currently retails at £20.95~ for just 6.5–7.5kg, which is nearly half the wood for well over double the price.
For that money, here's what you're getting less of:
- Species is rarely stated - That same supermarket net is described only as "a mix of seasonal hardwood," with no indication of what's actually inside. It might be a good burning wood, or it might include faster burning, lower heat species like alder or sycamore mixed in. You won't know until you're lighting the stove.
- We only sell what we'd burn ourselves - Every net is one clearly labelled species of either Beech, Oak, Hornbeam, or Birch, so you know exactly what heat output and burn time to expect.
- Consistency adds up over a season - A mixed, unknown species net that burns fast means more trips to top up the woodstore, more logs used overall and more time and money spent.
The Bottom Line
If you want a fire that lights easily, burns hot, and doesn't leave your chimney or your windows covered in soot, moisture content is very important. A moisture meter takes the guesswork out entirely, but the checks above will get you close.
And if you'd rather skip the checking altogether, that's exactly what kiln drying is for.