Firewood species and BTU
Water oak firewood: BTU, weight and seasoning
How much heat water 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 26.4 million BTU per cord at 20% moisture (27.9 GJ).
- A seasoned cord weighs about 4,300 lb (1,950 kg).
- Season it for at least 11 months.
- Ash: low. Coals: very high. Burn time: very long.
Heat per cord
Water oak is a hardwood. At 20% moisture, a full cord holds about 26.4 million BTU of heat (27.9 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.
That ranks water oak 258th of the 558 species in our tables, from the hottest down.
Weight and density
A full cord of seasoned water oak (20% moisture) weighs about 4,300 lb (1,950 kg). Freshly cut, the same cord weighs about 5,160 lb (2,340 kg): the difference is water you don't want to burn.
Its specific gravity, a measure of density, is 0.73. Denser wood packs more heat into each cord.
Seasoning time
Split and stacked off the ground, water oak needs at least 11 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 water oak 6 out of 10 as firewood: a good choice.
Similar firewood
Other species to compare with water 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 water oak good firewood?
Yes, it is good firewood. We rate water oak 6 out of 10.
How long does water oak take to season?
At least 11 months, split and stacked, to reach about 20% moisture.
How much does a cord of water oak weigh?
About 4,300 lb (1,950 kg) seasoned, and about 5,160 lb (2,340 kg) green.
How many BTU are in a cord of water oak?
About 26.4 million BTU (27.9 GJ) per full cord at 20% moisture.
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