The actual difference
Both are ready to burn the day they arrive. That is the first thing to say, because a lot of firewood marketing implies seasoned wood is somehow half-finished. It is not. The difference is how the water came out and how far down it went.
Seasoned firewood is split and stacked under cover, and the Dorset weather does the rest over a year or more. Air moves through the stack, the wood gives up its moisture slowly, and it comes out somewhere around 20% moisture content — dry enough to light and burn properly.
Kiln dried firewood goes into a heated kiln for a few days instead. The heat drives the moisture out faster and further, and it comes out consistently under 20%, usually a good way under. It is the same species, off the same jobs, cut to the same 8 to 10 inches. Only the drying is different.
Seasoned is air-dried and ready to burn. Kiln dried is oven-dried, drier still, lights faster and burns hotter from cold. Neither is "unseasoned" — that is a separate product entirely, sold deliberately green for people drying it themselves.
What the moisture actually does
Every litre of water in a log has to be boiled off before that log gives you useful heat, and it takes heat from the fire to do it. That is the whole of the moisture argument, and it explains almost everything people notice about wet wood.
- It lights slower. A cold stove needs a fast, fierce little fire to establish a draught up the flue. Damp wood cannot provide it.
- It burns cooler. Below roughly 260°C the smoke does not ignite, so a chunk of the fuel goes up the chimney unburnt instead of heating the room.
- It blackens the glass. Those unburnt particles land on the coolest surface in the stove, which is the glass.
- It builds creosote. The same particles, cooled in the flue. Creosote is what catches fire in a chimney fire.
Seasoned wood at 20% has already dealt with most of this. Kiln dried has dealt with more of it. The gap between them is real but modest — the gap between either of them and a damp log off a neighbour’s hedge is enormous.
What it costs
Here is every price we charge for both, so you can see the actual gap rather than guessing at it.
| Load size | Seasoned Mixed | Kiln Dried | Difference |
|---|---|---|---|
| Net bag 0.03m³ | £12 | £15 | £3 |
| Barrow bag 0.275m³ | £70 | £80 | £10 |
| Ton bag 1.1m³ | £120 | £145 | £25 |
| Half transit 2.2m³ | £230 | £250 | £20 |
| Full transit 4.4m³ | £420 | £450 | £30 |
| Per cubic metre, full load | £95 | £102 | £7 |
In a full transit that is about £7 a cubic metre, or roughly 7%. It is not the gulf people expect. For a household burning three or four cubic metres a winter, choosing kiln dried over seasoned costs about £30 across the whole season.
All five firewoods, all five load sizes, and the price per cubic metre so you can compare properly.
Which to choose
Buy kiln dried if…
- You light the fire at short notice rather than planning it. Kiln dried gets going from cold noticeably faster.
- You have a small or fussy firebox that struggles to get properly hot.
- You care about the glass staying clear.
- You are cooking on it — a pizza oven needs the drier wood to reach and hold 450°C.
- Your wood store is honestly a bit damp, and you want the driest possible starting point.
Buy seasoned if…
- You burn regularly and predictably, so the stove is often already warm.
- You are buying in bulk and the price per cubic metre matters.
- You have somewhere genuinely dry to keep it.
- It is for a fire pit, a chiminea or an open fire, where you are not chasing the last few percent of moisture.
- You want a stove load that lasts the winter for the least money.
Or, sensibly, buy both
This is what a lot of our regulars do and nobody ever suggests it, so here it is: a bulk load of seasoned mixed for the body of the winter, and a few net bags of kiln dried for lighting.
You get the cheaper wood for the 90% of burning where it makes no difference, and the drier wood for the ten minutes where it does — a cold stove on a wet Tuesday in January. A full transit of seasoned mixed plus four nets of kiln dried is £480, against £450 for a full transit of kiln dried alone, and you end up with more wood and an easier light.
The 7% price gap between our seasoned and our kiln dried is much smaller than people assume, and the gap between either of them and genuinely wet wood is much bigger. Whichever you pick, keep it dry once it is with you — off the ground, covered on top, open at the sides.