What is greenwood?

‘Greenwood’ in this context refers to the working of wet or unseasoned wood that has recently been felled. Freshly cut wood contains a lot of water which will eventually evaporate, causing shrinkage. This ‘wetness’ can be of benefit in some green woodworking joints which rely on shrinkage to produce a tight fit. Wood can still be considered green for up to a year if left in a round log before being worked.

Techniques for shaping green coppice wood follow the grain, producing softer flowing surfaces – but increased strength, as the wood’s linear fibres remain intact. Greenwood working requires a different set of skills and tools from modern carpentry, as well as a closer understanding of the nature of wood and the character of different trees. Originally, all woodworking would have been green. These techniques evolved to shape unseasoned wood when it was soft and pliable, and the wood simply dried over time after it had been worked.

Once a piece of wood is seasoned, it is no longer referred to as green. Seasoned traditionally meant air-drying planked timber for at least a year. During this time the moisture content drops below decomposition level (below 21%) and a substantial amount of shrinkage takes place. Nowadays, most timber is kiln-dried down to below 12% moisture content, and modern carpentry relies almost exclusively on supplies of milled and kiln-dried timber.

Greenwood working techniques generally involve splitting and working with the grain rather than sawing through it, causing minimal distortion of the wood during shrinkage and seasoning. The techniques of Greenwood working cross many disciplines, from boat and house building to expressive arts, furniture-making and home crafts. Many of our customs, expressions and works of art have been inspired by these traditions. Green oak timber framing is also enjoying a revival. This technique is mainly used for barn and house construction. Frames are assembled from large sawn or hewn timbers connected with mortise and tenon joints and fixed with wooden pegs.

What are the benefits?

Green wood is soft and therefore easy to work with hand tools; this reduces the need  for power tools, which are noisy, dangerous, require electricity and can cause dust-related respiratory problems. Work can be done outdoors in the fresh air directly after the tree is felled – it’s healthy, and gives a sense of connectedness to the trees and to the natural environment generally.

Most greenwood working products are made from coppiced hardwood. Coppicing is the practice of cutting back trees before they reach maturity, after which they re-grow. Trees managed in this way have been known to survive many times their normal life span. Humans have been coppicing for so long that some insects and plants have evolved to prefer this type of habitat. Coppicing is a sustainable system of woodland management.

Most general building timber now is imported softwood. Greenwood working has developed around using local wood which means lower embodied energy – in other words, the amount of energy used in its harvesting, transportation and processing. For example, sawn timber has an embodied energy value of around 580kW per tonne, and if it is imported it may be 3 times this much. Brick has an embodied energy value 4 times the above figure, cement 5 times, glass 14 times, steel 24 times, aluminium 46 times and plastics 77 times. Wood that has been hand cut has an embodied energy rating of practically zero.

We have very little woodland left in Britain and most of what we do have is softwood plantation. Native British broad-leaf woodland supports a richer diversity of wildlife. Re-establishing economic demand for these woodlands encourages their planting and protection. Every bit of wood used from Britain may also mean less deforestation or illegal logging elsewhere in the world.