Size of tree and type of forest Small trees have average heights up to 15 m, medium 15 to 30 m, and large over 30 m. Diameter at breast height is stem diameter at 1.3 m above ground. For example, sapwood and heartwood colour, grain, figure. Green density is the density of wood in the living tree, defined as green mass divided by green volume, and is useful for estimating transport costs. It varies with season and growing conditions.
Basic density is oven-dry mass divided by green volume.
This measure has the advantage that moisture content variations are avoided. The figures given are shrinkage from green to 12 per cent moisture content, before and after steam reconditioning treatment. Reconditioning recovers any cells that may have collapsed during drying, and is essential for species such as the ash-type eucalypts. 5. Workability Comments are made on the comparative ease or difficulty of turning, nailing and bending, on susceptibility to splitting and other working properties. Class 1 gives more than 25 years life, Class 2 gives 15 to 25 years, Class 3 gives 8 to 15 years, and Class 4 less than eight years.