Firewood species and BTU
Willow oak firewood: BTU, weight and seasoning
How much heat willow oak gives, what a cord weighs, how long it takes to season and how it burns.
Last reviewed November 4, 20262 min readBy Lorne Wanamaker, firewood seller
On this page· Heat per cord
Quick answer
- About 28.1 million BTU per cord at 20% moisture (29.6 GJ).
- A seasoned cord weighs about 4,570 lb (2,070 kg).
- Season it for at least 12 months.
- Ash: low. Coals: very high. Burn time: very long.
Heat per cord
Willow oak is a hardwood. At 20% moisture, a full cord holds about 28.1 million BTU of heat (29.6 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.
That ranks willow oak 210th of the 558 species in our tables, from the hottest down.
Weight and density
A full cord of seasoned willow oak (20% moisture) weighs about 4,570 lb (2,070 kg). Freshly cut, the same cord weighs about 5,480 lb (2,490 kg): the difference is water you don't want to burn.
Its specific gravity, a measure of density, is 0.77. Denser wood packs more heat into each cord.
Seasoning time
Split and stacked off the ground, willow oak needs at least 12 months to dry to about 20% moisture.
Wood dries faster once it is split and stacked with air around it. A moisture meter on a fresh split face tells you when it is ready.
How it burns
- Ash: low
- Coals: very high
- Burn time: very long
We rate willow oak 6 out of 10 as firewood: a good choice.
Similar firewood
Other species to compare with willow oak:
- Black oak: 26.1 million BTU per cord
- Bur oak: 26.4 million BTU per cord
- Chestnut oak: 27.4 million BTU per cord
- Holm oak: 35.0 million BTU per cord
Where these numbers come from
The heat and weight figures come from our firewood tables, worked out the same way for every species at 20% moisture. See how we calculate them.
Questions
Is willow oak good firewood?
Yes, it is good firewood. We rate willow oak 6 out of 10.
How long does willow oak take to season?
At least 12 months, split and stacked, to reach about 20% moisture.
How much does a cord of willow oak weigh?
About 4,570 lb (2,070 kg) seasoned, and about 5,480 lb (2,490 kg) green.
How many BTU are in a cord of willow oak?
About 28.1 million BTU (29.6 GJ) per full cord at 20% moisture.
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