Seasoned firewood is important
The key to a successful fire is to ensure the fuel is as ‘dry’, or as ‘seasoned’, as possible. Green wood can hold its own weight of water, and it takes time to get rid of this.
While surface water does not really matter because that will evaporate quickly, it is important to reduce the sap levels within the cell structure of the wood itself, and that takes some time. It is recommended that softwoods are seasoned for at least 12 months, to provide the optimum burning efficiency.
Gathering and stacking wood in the open air over the summer period is advantageous because the warmth of the sun and good air circulation will automatically evaporate some of the sap. When the wood gets wet from seasonal rain, the rain water replaces sap and because water is more quickly evaporated, the fuel dries faster. You should obtain your wood far enough in advance to allow for the extra seasoning it is likely to need.
If you are starting with “green” wood, here are a few steps to take to ensure that it will be just right when you come to burn it!
- Split larger logs, so that the largest surface area of the internal wood is exposed to the atmosphere.
- Stack the wood loosely, on bearers, with the ends facing a prevailing wind.
- Cover with a plastic sheet or similar to create a warmhouse effect, with the sides open to allow air to flow through.
- Leave the bark on split wood - it helps to provide natural protection from rain.
How to know if your firewood is dry
- Knock two pieces of wood together. If it “rings” rather than “thuds” it is likely to be dry.
- Look for radial splits at the end of a piece of wood. These are a sure way to identify dry wood.
- Place a piece of wood on a good fire base. If three sides are burning within 15 mins, the fuel can be considered “dry.”
- Use a moisture meter, dry fuel is considered from 15-20% moisture content
Fuel that you must not burn in your Metro
- Do not use wood until it is fully seasoned
- Do not use rotten wood - it has very little useful heat in it and rot = moisture!
- Do not use salt borne drift wood. The salt will cause damage to the wood fire and flue system.
- Do not burn chemically treated timbers. The chemicals may be noxious and pose a health risk
- Old painted timber can also pose a threat if it has been painted with lead based paint.
- Don’t burn domestic rubbish, glossy paper or magazines as they produce harmful chemicals and creosote
- Coal must not be used as a fuel
Burning incorrect fuel can produce harmful chemicals that can damage the firebox and flue system.
How to store your firewood
Store firewood in a well ventilated, covered location. If possible, store firewood off the ground, on a pallet, layer of bricks, stone, or plastic sheet to prevent moisture from being drawn up into the firewood. Firewood stored in a criss-cross pattern allows for greater air circulation. If firewood has to be stored in the open, keep a few days supply under cover. Seasoned firewood wet by rain will dry again within a few days.