English elm firewood: BTU, weight and seasoning

Heat per cord

English elm is a hardwood. At 20% moisture, a full cord holds about 20.6 million BTU of heat (21.8 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.

That ranks English elm 404th of the 558 species in our tables, from the hottest down.

Weight and density

A full cord of seasoned English elm (20% moisture) weighs about 3,350 lb (1,520 kg). Freshly cut, the same cord weighs about 4,020 lb (1,820 kg): the difference is water you don't want to burn.

Its specific gravity, a measure of density, is 0.57. Denser wood packs more heat into each cord.

Seasoning time

Split and stacked off the ground, English elm needs at least 9 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: moderate
• Coals: high
• Burn time: long

We rate English elm 3 out of 10 as firewood: it burns, but denser species give more heat for the same work.

Similar firewood

Other species to compare with English elm:

• American elm: 20.4 million BTU per cord
• Cedar elm: 23.9 million BTU per cord
• Dutch elm: 21.0 million BTU per cord
• Red elm: 21.9 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