You’ve just bought a new stove, or fireplace, or something else with a capacity to burn the brown stuff. But how do you go about deciding what to burn, and how much to buy, and how much to burn, and when, where and why? Relax, we’ve got you covered. Here is everything you need to know about burning wood.
Which type of wood do I burn?
There are so many different kinds of wood out there to burn. Each gives off a different aroma and burns at different speeds. The received wisdom holds that hardwood is best, burning with greater output than softwoods with a slower, long lasting burn. This is owing to the density of hardwood relative to softwood. They both have the same calorific value per KG but hardwood is twice as dense on average, meaning twice the output for the same weight of softwood.
While this is a good rule of thumb, it isn’t necessarily true. There are many factors to consider such as the renewability of the wood source, the specific heat output, ease of burning and how many sparks its likely to produce (no one wants a singed carpet). We have written previously about specific species of wood and how well they burn here. But here is a rundown of some of the best woods to burn:
Ash, Birch, Cedar, Cherry, Hazel, Holly, Larch, Laurel, Maple, Pear, Thorn, Walnut and Yew.
Why moisture content matters more than anything
DO NOT BURN MOIST WOOD. This is the most important rule of the wood burning club, moist wood is problematic for many reasons. First and foremost is that burning moist, green or fresh wood creates an acid vapour called creosote that will build up in your chimney or flue, and over time this can either compromise the structure of your chimney or catch fire causing a deadly chimney fire.
Secondly, it is horrifically inefficient, water absorbs heat as it transitions into the gas phase, so essentially when you burn wet wood a lot of the energy of the burn is being wasted on into turning water into a vapour, which flies straight up the chimney.
For these reasons it is important you only burn seasoned or kiln dried wood. Kiln dried wood has moisture levels lower than 25%, and it is strongly recommended that you do not burn anything over 30%. Most suppliers will indicate the moisture content of the wood they are selling, but if not make sure you ask, do not burn what you don’t know!
Only burn seasoned wood
If you have cut the wood yourself from a natural source it is important that you season it. This is essentially a drying process, although not quite as intense as a kiln, but it’s doubtful any amateur lumberjacks have access to an industrial kiln, so this is the best way.
When you season logs make sure they are elevated from the ground, and covered from the rain, but still exposed to the wind and the sun. This is vital. Covering them with a tarp will allow mould and fungi to grow in the damp conditions where water cannot escape. Covering your logs for short periods of time if torrential downpours are expected is fine. Just be sure to uncover them after the rain has passed.
We understand that it must be tempting to burn any old wood that you find lying about the forest. But it really is important you only burn what you know, either because you purchased it from a reputable vendor, or because you chopped it and seasoned it yourself. This can be the difference between a having a chimney fire or not. Be sensible.
Moisture content is variable, and is a good reason not to buy wood in bulk by weight. Wet wood obviously weighs more than dry wood, and how much more will depend on the species. There is a lot of data available on how much this varies from species to species. (See here for a comprehensive rundown). Typically, wood is sold in bulk in units known as ‘cords’. This is a specific unit of volume and typically weighs around 4000lbs, or 1814 Kg. But 4000lbs of wet wood will be a lot less than 4000lbs of dry wood, so if you buy in bulk make sure you buy according to defined units of volume instead of weight.
Click here to view our range of kiln dried hardwood.
How do I store my wood?
Wood storage is always something of a conundrum. The best solution seems to be: buy your wood in bulk and store the majority of it outside. As mentioned above do not keep in a watertight environment, even kiln dried wood has some moisture in it and this has to be allowed to breathe, or else fungus and mould may spoil it completely. There are many stylish dedicated outdoor log stores out there that serve this function, and look good doing it.
Once you have stored the majority of your logs outdoors, its useful to have to have some to hand indoors for quick burning. Many stoves have inbuilt logstores, but if not there are also many stylish indoor fireside log stores that you can purchase to keep them tidy and to hand.
What else can I burn?
Steady on you pyromaniac. As we’ve mentioned before, burning anything other than seasoned, dried wood could spell disaster for your chimney and your stove. But there are alternatives to wood, Hotties heat logs are the world’s first eco logs, made of wood waste these are 100% renewable and will not spit or spark or damage your chimney. These bad boys have moisture contents as low as 5%. This is as low as charcoal, meaning you will have long lasting, reliable warmth every time. These are a fantastic and affordable alternative, maybe even better, than burning the real thing.
Just remember: Safety first!