Drying your Firewood
Drying your own firewood
More and more people are turning to wood as a domestic fuel which is great news for the environment. Wood can be described as carbon neutral as the carbon given off when it is burnt is equal to the amount absorbed by the tree as it grew. Burning locally produced or homegrown firewood is a small but important step in fighting climate change but to get the best out of your firewood and to ensure that emissions are kept to a minimum then that wood must be properly dried.
Drying your firewood or “seasoning” as it is more usually termed is a relatively simple but vital process to ensure that you get the most from your logs in heat output and a clean burn with fewer emissions. A newly felled tree, even one which has fallen in a winter gale and lain undisturbed for several years, can contain as much as 65% water content. The water or moisture content depends on the species of tree and at what time of year it was felled. In mid winter a tree sends most of its sap to the roots which makes it the ideal season to begin collecting firewood.
If you were to attempt to burn that firewood immediately, in a stove or open fire, the results would be disappointing and the long term effects could be disasterous to your health. An article describing the dangers of burning unseasoned firewood can be found here
Newly felled firewood logs need to be seasoned. The art and knowledge of drying your own firewood was once part and parcel of everyday life. Done correctly it can result in a cheerful blaze with lots of heat and very little smoke or other harmful emissions. The time taken to achieve that very much depends on the tree species and the time of year it was collected. Oak firewood logs can take up to 2 years to fully season before the moisture content is low enough for it to burn with a good flame. Softwoods 6 months to a year. Nothing is so disappointing than placing logs into a new stove only to find that they either refuse to light or they just sit and smoulder without giving off any heat.
Drying your firewood can save you money but do bear in mind that it will be impossible to achieve the moisture content of our homegrown mixed hardwood kiln dried logs which typically are around 15% or less. The best you can hope for is around 20% to 25% moisture content. At that level of water content they will burn but not as efficiently and the heat given out will be less.
Cheap is not always best!
A few weeks ago we were delivering another order of our home grown mixed hardwood kiln dried logs. The customer had previously bought in a load of logs at a very good price from a local supplier in the next village. Unfortunately for him, as with most things in life, you really do get what you pay for and firewood logs are no exception. This cheap load of logs contained so much moisture that they absolutely refused to burn. Instead they just smouldered and gave off amazing amounts of blue wood smoke. The flue couldn’t cope and smoke was billowing into the room every time he tried to light the stove!
A quick check with our handy moisture meter confirmed his worst suspicions. These logs had an average moisture content of just over 45% and what he had bought was unseasoned firewood, probably only recently felled. What was needed was a quick lesson in drying your firewood.
Indoors or out?
The obvious place to begin the process of drying your firewood would appear to be inside a shed or garage. Wrong! Unseasoned logs need to be exposed to the elements to drive out the water contained within it’s fibres. The more exposed the better and the more air circulating around them the quicker they will season and be fit to burn.
The ideal spot would be a south facing exposed situation. Your unseasoned logs should be stacked in such a manner so that air circulates freely above, below and through them. This means raising them off the ground in some way and ensuring that they are not resting against a wall or fence. Again, the key to drying your firewood is air circulation.
The exposed ends of the logs should face outwards. The logs should be split so that they are no more than six inches in diameter. Any logs with bark remaining should be stacked with the split face uppermost. The stack should not be too high but rather long and low.
Covered or not covered?
How do I know when my logs are seasoned?
Drying your firewood can be rewarding, save you money and turn that useless pile of wet logs you’ve just purchased into useable firewood. Properly seasoned firewood should make a ringing noise when two logs are banged together. If all you get is a dull thud then more seasoning time is required. Look for radial cracks in the end of the logs. This is a sign that the moisture has been driven out and removed by the air circulating freely around them. It’s at this point that the logs can be placed into your log store ready to burn.
How long will it take?
Drying your firewood can take up to 2 years depending on the species and the time of year the tree was felled and/or cut up for logs. Too long a drying time can result in the removal of resins within the wood. These resins contain a lot of energy and provide a lot of heat during the burning process.
If it all sounds too much or if you simply do not have the space to begin drying your firewood then Border Biomass Fuels is at hand to help. We supply the finest home grown mixed hardwoods which are seasoned in the open air and then kiln dried to produce the perfect kiln dried log ready to burn now. We’ll even deliver and stack them for you too at no extra cost. Our homegrown kiln dried logs are available in our online shop HERE