Fuel for Thought

Seven Things to Know about Firewood

Whether you light a blaze to stay toasty or to serve as the backdrop for a romantic evening, safe and economical wintertime fires can be made or broken by the wood you use. Wayne Clatterbuck, a professor at the University of Tennessee, Forestry Extension Service, says effective fires all have one thing in common: the right wood. Here are tips on the art of choosing, storing, and using firewood that will make future fires cozy and secure.

1. Consider the real cost of "free" firewood

Tempted to chop up that dead tree you found in the woods and toss it on your woodpile? Or bring back a truckload from a friend's place out of state? What seems like a savings can instead spread disease and harmful insects to healthy, previously unaffected vegetation—like the stuff in your own yard. Don't import trouble.

2. Don't burn green wood

Drying firewood is known as seasoning. Green (wood that hasn't dried long enough) or unseasoned firewood contains about 60 percent water. Much of the energy released by burning green wood simply dries it, which gives you a wimpy, smoky blaze. When burned, green wood also produces more creosote and pollutants than the dry stuff. Creosote (a mix of chemicals) can build up in fireplaces, leading to chimney fires and more pollution.

3. If you season your own firewood, make sure it dries long enough

Season firewood for six to nine months on average. Bigger chunks require longer drying times. When purchasing firewood from a dealer, specify seasoned or unseasoned firewood when you order. Firewood sellers carry both. Seasoned wood will have cracks in the cut ends and bark that falls easily from the log. It also weighs less than green.

4. Store firewood properly

Don't stack it inside your home, garage, or outbuildings. Wood dried indoors fosters mold and mildew, not to mention creepy-crawlies that live in the wood. Keep it away from the side of your house too. Termites adore firewood. And never, ever spray it with insecticide. Sprayed wood can put out toxic gases when burned. Clatterbuck recommends keeping the wood up off the ground, putting it on pallets if you have them, and after it seasons, covering it with a tarp, especially in humid or wet climates.

5. Understand how firewood is measured

Firewood is sold by volume, not weight, and not all cords are created equal. The amount of wood in a cord varies according to the wood's length and cut. Split logs in a cord contain more wood than cords composed of unsplit logs because it's packed more tightly. A face cord or rick contains one-third as much wood as a full cord. Full cords have 128 cubic feet and weigh one to two tons.

6. Know what to burn

Don't throw those construction scraps or pieces of driftwood in the fireplace or wood stove, especially if they've been painted or treated. They may contain chemicals like arsenic that can be poisonous when burned. Other no-nos: plywood, OSB (oriented strand board), plastic, and glossy magazines. Newspaper, however, is fine as a fire starter. Clatterbuck says many softwoods like pine, red cedar, or spruce contain resins that make them pop and spark. Most hardwoods—such as red and white oaks, ash, beech, and hickory—don't.

7. Don't expect heat from those wax fire logs you buy in the grocery store

Those prepackaged fire logs make fires convenient, but don't look for any real warmth. They're constructed of industrial by-products, so they don't generate heat in the same manner as wood.

Carole Moore writes from her home in North Carolina.