Red spruce firewood: BTU, weight and seasoning

Heat per cord

Red spruce is a softwood. At 20% moisture, a full cord holds about 16.3 million BTU of heat (17.2 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.

That ranks red spruce 514th of the 558 species in our tables, from the hottest down.

Weight and density

A full cord of seasoned red spruce (20% moisture) weighs about 2,580 lb (1,170 kg). Freshly cut, the same cord weighs about 3,510 lb (1,590 kg): the difference is water you don't want to burn.

Its specific gravity, a measure of density, is 0.43. Denser wood packs more heat into each cord.

Seasoning time

Split and stacked off the ground, red spruce 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: moderate
• Coals: moderate
• Burn time: moderate

We rate red spruce 1 out of 10 as firewood: it burns, but denser species give more heat for the same work.

Similar firewood

Other species to compare with red spruce:

• Black spruce: 16.9 million BTU per cord
• Engelmann spruce: 14.4 million BTU per cord
• Norway spruce: 15.2 million BTU per cord
• Sitka spruce: 15.9 million BTU per cord

Where it grows

Eastern North America

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