I’ve been thinking about firewood quite a lot recently – and not just as an excuse to post my favourite view of the commons with my favourite landrover, well one of my favourite landrovers, in the photo. We’re still waiting and hoping for Winter to be overwhelmed by Spring, but despite the longer evenings and the sun higher in the sky it snowed again last week. It’s been the coldest March for at least 50years around here.
With it being so cold we’re still burning a lot of wood and dry firewood is at a premium right now. I’ve ended up burning some of the wood I’d put aside to make my my first charcoal of the season - it’s never easy to predict just how much firewood you will need each year.
To eke out my supplies I’ll take advantage of any dry seasoned wood I come across. The load of well seasoned Sweet Chestnut in the back of the Landrover had to be removed while I was mending the stock fencing and it seemed a shame to waste it.
As I’m burning the last of my stored and seasoned dry firewood it’s a very good time to be starting to prepare next years and I’m also trying to get ahead with preparing some wood for my charcoal making through the summer.
Just about any wood will burn once it’s dried out or seasoned though some woods will burn more easily due to their density and smell more attractive as they burn. This is a collection of Beech, Rowan, Birch and Sweet Chestnut being split ready for the sun to season it – provided of course that we do get any sun this year. These are all good firewoods but they are not dry enough to burn efficiently yet and need the summer and strong sunlight to reduce the moisture content.
Just to hammer this home – if you try to burn 10Kg of only partially seasoned wood at 30% moisture – then you will have to boil off 3Kg of water. Boiling off the water reduces the temperature and efficiency of your fire as well as condensing with other volatile chemicals in your chimney to form creosote.
Much better to let the summer sun dry your firewood to 20% moisture content or below if possible – but it’s hard to go much drier because of the ambient moisture content in the air. Even if you do dry the wood completely, unless it’s stored in an atmosphere with zero humidity it will start to soak up moisture again quickly.
When the wood is dry enough it will burn much more efficiently and deliver more heat – the volatile chemicals are also more likely to be burnt increasing the efficiency of the burn and reducing the deposits in the chimney.
Once your wood is drying nicely it needs to be stacked to protect it from the rain – but still allow the sunlight to continue drying it and the wind to blow through it.
In our climate some kind of roof on the stack is necessary as well as a base to lift the stack off the ground and prevent moisture from wicking up into the wood from the ground. This stack is self supporting in the Bavarian style with a double wall of split logs curved around at the corners. The pallets on top allow an air space for the wood to continue drying and stay dry until it’s needed.
With so many other jobs to attend to it’s hard to give the firewood the attention it deserves. But we’ve struggled to heat our cottage this winter and that’s a good reminder that I need to give my firewood every chance to dry if I want to stay as warm as possible through next winter.