Looking to heat your home with wood?
You’re not alone. It’s a great choice to save money and keep away the winter chill.
Many people, especially in rural areas, use wood stoves to supplement their heat or as their primary heat source. Heating your home with firewood is also a great way to keep your heating bills down.
If you are using firewood to heat your home, however, there are some things that you should know about firewood. Knowing how to season firewood properly will keep you safe and prevent problems. Because knowing how to season firewood is so important, here are a few tips to help you to get it right.
Why You Need to Season Your Firewood
It is a good idea to make sure your firewood is thoroughly seasoned before burning it. Unseasoned firewood produces more creosote which sticks to the inside of chimneys and can potentially cause a fire. Greenwood has about a 50% moisture content, while seasoned wood has about 15-20% moisture content. Unseasoned firewood also has a higher moisture content that can make it difficult to light and difficult to burn. Much of the energy produced by your fire or campfire will get used up by drying the moisture from the wood and can also produce a lot of smoke. Conversely, dry firewood lights easier and burns hotter.
It is also important to note that moisture encourages mold growth. When you chop and stack your wood to dry, you reduce possibility of mold growing on your firewood. You then reduce the likelihood of bringing mold into your home.
How Wood Dries
Wood is essentially made up of tiny straws of material that run the length of the tree. These straws carry water in them. There is also water contained within the cells that compose these straws. When you chop a tree down, the water contained in these straws is the first to go, leaving only water in the cells of which the straws are composed. The wood is still not fully seasoned when water is sitting around in these cells. Once the water starts to leave the cells, shrinking and cracking occur.
You should be careful to not dry the firewood longer than is necessary, as this can cause the volatile esters to leave the wood. The volatile esters are a waxy substance that contain much of the heat energy. You will know your firewood has been seasoned enough when the wood produces a “clink” when knocked together instead of a “thud”.
How Different Species Dry
Different species of tree woods will try due to varying chemical composition and cell structures. Knowing the properties of the wood species can help you best determine the amount of time necessary for the wood to properly dry. Don’t expect your wood to dry fast in a month of two. In general, softwood trees such as pine take between 6 and 18 months to fully season. Hardwoods, such as oak and maple, can take between one and two years. Greenwood like pine and bird will take 6 to 12 months to fully season.
During the winter deciduous trees send their sap into their roots. This means that a deciduous tree cut down in the winter will require less time to season because most of the moisture is in its roots.
How to Season Firewood
Once you have a pretty good idea of how long it will take your wood to season, there is nothing left but to split your firewood and stack it to allow the seasoning process to begin. These six tips will help you get it right.
1. Plan ahead
You should calculate how much wood you will need to get you through the season and procure extra just to be safe. You should do this far enough in advance for the wood to be properly seasoned by the time that you need it. If you burn between 1-2 fires per week, 3 cords of firewood should be suitable. Keep in mind that a cord of firewood is a stack 4 feet high by 8 feet long by 16 inches deep.
2. Cut your wood to the appropriate length and width
You should make sure wood is three inches shorter than the firebox of the appliance you are putting it in. Usually cord wood is cut to about 16 inches in length. It should also be cut to between 3 and 6 inches in width for wood stoves and up to 8 inches for furnaces to get the best burn. For backpacking stoves that size needs to be much smaller.
3. Split your firewood
This allows air to get to more of the surface. We’ve written a guide about how to split firewood for our readers.
4. Stack and expose your wood
Stack your wood in such a way as to allow air to circulate through the stack. Put the stack in a place where it can get maximum sun exposure. This will all help it to dry.
5. Keep your wood off the ground and away from walls
Keeping your wood off the ground and away from other surfaces will help air to circulate beneath the stack, also helping it to dry. Try placing supports on the ground such as additional pieces of wood, cinder blocks or even pallets for stacking your wood.
6. To cover, or not to cover?
The firewood community is divided into two camps. On the one hand you have the people who believe that you must cover your firewood with a tarp or plastic to protect it from the rain and the elements as it dries. You simply leave the ends exposed so that air can circulate through your stack. On the other hand you have the people who believe it is completely unnecessary to cover your stack. As long as you keep the wood off the ground and away from walls, the wood will dry regardless because water has a lot harder time getting into the dead wood cells than getting out.
How to Tell If Wood Is Seasoned
While it is possible to gauge how dry wood is by using a moisture meter, it is possible to bypass the complicated technology. With a little patience and practice, you can learn to tell when wood has been properly seasoned. Here are some tips.
1. Hit two logs together
If you hear a “clink” rather than a “thud” then your wood is probably dry.
2. Check the ends of the wood for radial cracks
You should begin to see cracks that run from the heartwood at the center of the wood extending out to the sapwood. This cracking begins before the wood is fully seasoned however, so you should not use that as your only measure.
3. Wood changes color as it seasons
You may start out with wood that is a white or cream color. With time it will season to a yellow or gray. Wood turns cream and grey over time because of exposure to oxidation from the wood drying out and UV exposure from being exposed to the sun.
4. Smell for sap
Fresh wood will have a strong, sappy odor. Dry wood will be less pungent. Water molecules carry the scent of the sap and disperse it. Less water in the wood means that the sap scent will not be as pungent.
5. Check the bark
The bark will be loose on seasoned wood. As wood dries, the bark detaches because the cells inside the log die from a lack of water and nutrients. Once these cells die, the bonds between bark and the wood are weakened.. The result is that a seasoned pile of wood will have less bark on it than fresh wood.
6. How heavy is it?
Moist wood will naturally be heavier than its dry counterpart due to water in the cells. Water is a fairly heavy substance. There will be a noticeable different in weight of a few pounds per log between a fresh log and a seasoned log due to the extra water.
7. Try to burn a piece
Dry wood should burn pretty easily. Unseasoned wood will be difficult to light or burn and will hiss in the fire as water is steamed off.
Knowing how to season firewood can provide you with a sustainable heat source all winter long. Once you have split and seasoned your wood and made certain that it is properly seasoned, then you are free to enjoy the fruits of you labors. Having a warm house to come home to in a cold season is the best reward of all.