Aside from the sensory appeal of fire, one of the main reasons that stoves have seen a resurgence in popularity is the fact they have no associated energy bills. Though you’ll need to spend money on the occasional maintenance of your system, a popular way of keeping overall running costs low is by seasoning your own wood, whether it’s wood you’ve sourced yourself or cheaper unseasoned logs from suppliers.
What is ‘seasoning’?
‘Seasoned’ firewood is timber that has been dried until it contains between 20 -25% moisture, with anything above that qualifying it as ‘unseasoned’. Seasoning can take a very long time depending on the type of wood you’re using; softwoods like pine can take between 6-12 months, whereas hardwoods like beech can take 2 years or longer! Purchasing unseasoned logs directly from suppliers is much cheaper than buying pre-dried wood, but it’s a time-intensive process that requires you to have enough storage space to carry out the process yourself. It’s also possible to season firewood with a sage and parsley rub, though this will have no effect on its moisture content and is a terrible waste of spices.
Why do I need to season firewood?
Burning unseasoned or ‘green’ wood on your stove is an absolute no-no on all counts! When unseasoned wood is burnt, the released water vapour contains some of the natural acids present in the wood which can corrode the inside of the flue and chimney liner, causing extensive damage to your system. Another very serious side-effect of burning green wood is that the evaporated water mixes with gases and soot particles in the chimney to create a sticky build-up of creosote. If left to accumulate, the creosote could ignite and start a chimney fire, which is why it’s important to get your chimney swept regularly if you often burn wood in your stove.
Should you need further convincing that burning green wood is a terrible idea, there is another, more practical reason not to do it: unseasoned logs burn really poorly. The higher moisture content present in unseasoned logs means that any of the heat you manage to produce is all used to drive the excess water out of the wood. You’ll be fighting an uphill battle trying to keep a fire going with unseasoned wood and it’s often more trouble than it’s worth. Simply put, there is never a good reason to use unseasoned wood on your stove.
How do I know if it’s seasoned and ready for use?
Once you’re more familiar with stove use, often you’ll be able to get a good idea whether wood is seasoned or not from sight and feel alone. Comparing on a side-by-side basis, the difference is quite noticeable.
A cross section of unseasoned wood will typically look brighter and have a ‘fresh’ look to it, possibly with a ring of green close to the bark. It might feel slightly damp and have a sap-like smell which indicates it’s been recently cut, and the bark will not easily lift away from the surface. A dead giveaway of unseasoned wood is that it will be difficult to burn and it will hiss as moisture is released – breaking off a small piece and testing it beforehand in the fire is a good way to avoid making a mistake.
Well-seasoned wood, on the other hand, will look darker and have more deep cracks running through the grain. The bark will often separate from the wood during the drying process and be much lighter compared to unseasoned wood due to the amount of moisture loss. Banging two pieces of wood together is another excellent indicator as to whether your wood is seasoned or not. The low moisture content of seasoned wood gives it a hollow sound on impact whereas green timber will make a dull thud.
It’s good to know what seasoned firewood looks like but for ultimate convenience, you’ll probably be better off purchasing a moisture metre which will do the hard work for you. They’re inexpensive and will give you a precise moisture percentage reading for your firewood, which is handy no matter how much experience you have with stoves and wood burners. Some firewood suppliers can be unscrupulous and sell timber as ‘seasoned’ even when it doesn’t quite make the grade, so in these instances, a moisture metre can be invaluable.
How do you season firewood?
Seasoning firewood isn’t difficult; it just requires storage space, a bit of preparation and, above all, patience.
The anatomy of a log store
Firewood is most often seasoned outside in a log store and there are innumerable styles, sizes and options available online, but for a more personal touch, you can always build your own. Whatever design you decide to plump for, it will need to have a roof to protect the firewood from adverse weather, and be well ventilated on at least two sides to allow a through-draught of air. It’s very important that the wood has adequate air circulation to make the drying process as efficient as possible. The log store should also be off the ground to ensure that the logs don’t get wet, and again, keep a good supply of air flowing through the base. Similarly, try not to push the log store up against the wall as this can prevent air moving around the logs.
Positioning your log store
Positioning your log store is also an important factor, however this can be tricky in smaller gardens. Always try to place the log store in a sunny, breezy location so that they have as much chance as possible to dry out. If you think that your log store will be exposed to heavy rain, you can cover your wood pile with a tarp, but you should always uncover it at the next convenient occasion to keep it ventilated.
Splitting and sizing your timber
Before you store your logs, you should make sure they’re cut to the right length for your stove. The Solid Fuel Association recommends that any log with a diameter greater than 6” should be cut before storing, and ideally you should be aiming to cut them down so that they are less than 4” thick. Cutting logs to the right size is not only useful to make sure they’ll be easy to throw into the fire, it will also help the wood to dry out quicker.
When your firewood is seasoned, bringing the logs into the house for a couple of days beforehand can help them to dry out further before use. Seasoning wood in the home is not recommended, especially as logs sourced from the great outdoors can be covered in bugs and mites. As you can see, seasoning firewood isn’t difficult, however if you’ve decided to go down this route, you always need to plan in advance – sometimes months and years at a time!
Image sources:
- http://www.phoenix-chimneys.co.uk/wp-content/uploads/2015/02/chimney-fire-prevention.jpg
- http://www.onemanandhislog.com/firewood/Log-store-built-quality-colchester.jpg