Those of you who enjoy the crackling fire outside in the fire pit, soon may be planning your transition to the indoor fireplace. Burning questionable quality firewood outside does not take away from the joy of sitting around the pit after dark, but it can make a big difference inside.
Whether you cut, split, and dry your own firewood, or you buy it for the winter, good management will reward you with more heat and less smoke. The heavier the wood (given the same moisture levels), the more heat will be released as it burns. All wood contains moisture. For good combustion, firewood will need to be kept for at least six to nine months outdoors and have a moisture content between 20 and 25 percent; this helps it burn well and not generate a lot of smoke.
We have all thrown a piece of unseasoned wood on a fire and then realized a real drop in heat output. Dry, seasoned firewood will provide about twenty percent or more heat than an equal amount of green or unseasoned firewood. It takes energy to burn off the moisture before the firewood will burn. It is not recommended that you burn green wood indoors in the fireplace. Green wood generates a lot of smoke, and, more importantly, creosote that can build up in the homes’ chimney. The key to a successful fire that provides the most heat is going to be that dry wood.
Seasoned firewood is easy to spot. The ends will be checked and have a gray color. This is important if you are buying your firewood. Firewood less than six inches in diameter can dry at the size they are; greater than that and the wood will need to be split in order to season.
If you are splitting your own wood to dry, stack it in a crisscross fashion to allow the air to circulate through the stack. If possible, do not stack directly on the ground, as the bottom layer will attract decay fungi and a number of insects. Because of this, do not stack the wood so close to the house that it touches the siding. Stacking it away from the house also will increase airflow. To avoid another insect surprise, don’t bring in any firewood that you can’t burn within a week. If wood is in the house for more than a few days, it may allow all kinds of insects that have overwintered to emerge and become nuisance pests indoors.
Firewood will need to be covered to keep rain and snow from being reabsorbed after the wood is dry. Use simple materials like a tarp or a waste piece of plywood. You want to be sure to secure it so it will not blow off, but not so much that it takes too much time to remove and put back on when you are stacking or removing wood to burn. The covering should extend down the pile at least a foot or extend past the edges protecting much of the wood.
Remember, the drier the wood, the more heat you will get back, so the longer you dry it and keep it dry, the more you benefit.
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.