What Kinds of Wood Are Not Good to Burn in a Fireplace?

Heat

• A fireplace does not draw the smoke up the chimney as well as a woodstove, so creosote buildup is a concern. A hot fire helps prevent creosote buildup by moving air up the chimney faster. Avoid woods that do not provide a hot fire, such as poplar, spruce, basswood, cottonwood, horse chestnut or willow. These woods, even well-seasoned, have heating values of less than 16 million BTUs (British thermal units) per cord of wood.

Seasoning

• Wood should be seasoned for at least one year before use in a fireplace, and preferably for two to three years. Unseasoned or wet wood contains too much moisture, which causes wood to smoke profusely. Smokey wood is not pleasant when burned in a fireplace, and increases creosote buildup dramatically. Unseasoned wood smells like the lumber aisle of a home improvement store and is still colorful with the bark firmly attached, while seasoned wood is gray and somewhat cracked, with peeling or loose bark. Unseasoned wood should be avoided at all costs.

Ease of Use

• Wood that is hard to split or start makes it harder to use in a fireplace. Wood usually needs to be split into smaller pieces for use in a fireplace. Woods with a dense, twisty or knotty grain, such as boxelder, beech, elm, catalpa or black locust, are difficult to split. How quickly the wood catches fire is a concern if you are not experienced with building a fire, and woods such as ironwood, beech, black locust, mesquite and oak are difficult to start.

Safety

• While sparks might be fun to hear snap and see flying out into the darkness when outdoors, they are dangerous, especially in an indoor fireplace. Resiny wood, such as red cedar, hemlock, juniper, larch, pine and spruce, produces many sparks. Use a fire screen at an indoor fireplace to prevent a house fire starting from a stray, unnoticed spark, and avoid using spark-producing wood outdoors as well, to help prevent forest fires.