Wood as a fuel is very versatile and increasingly popular ecological option. If managed correctly, the forestry plantation under an FSC scheme will be sustainable. It is usual to buy logs by volume and not by weight. The weight of freshly felled timber comes partly from water.
The wood we supply is predominantly hardwood and mainly Beech which is a dense good quality fuel. We have also been introducing some better quality softwoods such as Western Hemlock, which some of our older customers will remember is all we offered for sale when we first started the business in 1989.
We feel softwood as a fuel is the answer for the future sustainability of the firewood industry in Cornwall and the UK.
So what is seasoned firewood?
Essentially, it is making wood fit for burning – by reducing its water content – usually by leaving it for a period of time in the right conditions. All wood contains water. Freshly-cut wood can be up to 45% water, while well-seasoned firewood generally has a 20–25% moisture content. This does vary by region and storage facilities. Well seasoned firewood is more efficient, produces more heat, and burns cleaner.
If you try to burn green wood, the heat produced by combustion must dry the wood before it will burn, using up a large percentage of the available energy in the process. This results in less heat delivered to your home, and gallons of acidic water in the form of creosote deposited in your chimney. This can eat through the chimney lining and cause significant damage. The problem is that as wet wood burns slowly, with little heat, the chimney flue does not get a chance to warm up. There is little draw (air moving up the chimney) which doesn’t help the combustion, and the flue remains a cold surface on which the creosote condenses. Dry wood will burn hot – heating up the flue, creating a fast draw, and shooting the smaller amount of vapours out of the chimney before they get a chance to condense.
The first step we take to drive the water out of the wood is to cut it into lengths – let’s say about 12–18 inches long. Tree branches and trunks contain thousands of microscopic tubes which carry water from the roots to the leaves, and these tubes can stay full of water for years after the tree has been felled (or pruned). Cutting the wood to shorter lengths opens these tubes to the atmosphere which increases evaporation.
The second step is splitting any logs that are more than say six inches in diameter. This increases the surface area of the wood exposed to the elements and therefore also enhances drying. So the cutting and splitting of logs should be done as soon as possible after the wood is harvested – not just before you want to burn it.
If you have any questions about logs and firewood that we haven't covered here, please feel free to contact us and we will get back to you.