River birch firewood: BTU, weight and seasoning

Heat per cord

River birch is a hardwood. At 20% moisture, a full cord holds about 21.5 million BTU of heat (22.7 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.

That ranks river birch 387th of the 558 species in our tables, from the hottest down.

Weight and density

A full cord of seasoned river birch (20% moisture) weighs about 3,500 lb (1,590 kg). Freshly cut, the same cord weighs about 4,200 lb (1,910 kg): the difference is water you don't want to burn.

Its specific gravity, a measure of density, is 0.59. Denser wood packs more heat into each cord.

Seasoning time

Split and stacked off the ground, river birch 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 river birch 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 river birch:

• Downy birch: 22.8 million BTU per cord
• Paper birch: 22.3 million BTU per cord
• Silver birch: 23.4 million BTU per cord
• Yellow birch: 25.2 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