with timber conversion is two fold. Firstly carbon dioxide in the atmosphere is creating a warming blanket around the earth gradually increasing the overall temperature. The diagram below clearly shows that timbers adds 30 kilograms of carbon into the atmosphere with every ton of timber sawn. This is relatively small however when compare to the production of steel or aluminium. However it seems essential in the long term that trees are grown faster than they are cut down.THE GREEN HOUSE EFFECT ENERGY burned and carbon released for construction materials (Buchanan, A. H. 1990) Fossil fuel EnergyCarbon releasedCarbon storedMJ/kg MJ/m3kg/tkg/m3kg/m3Rough Sawn Timber1.58503015250 Steel 35266,00070053200Concrete 24,800501200Aluminum 4351,100,000 8,70022,0000SOFTWOODSoftwood differs from Hardwood in that is mainly is produced from plantations and is grown in a more sustainable fashion. A typical softwood tree reaches harvesting age between 10 - 30 years which is much quicker than old growth forest hardwood timber. The carbon released from milling softwood is similar to hardwood so still contributes to the green house effect, but at least in softwood plantations carbon is still being locked up in the form of timber. When hardwood is milled generally it is never replaced so the carbon that is released never gets extracted by new growing trees such as in plantation softwood.HARDWOODDurability is defined as the length of time a material will last in relation to weather, decay and general wear. The hardwoods investigated in this report all offer superior durability to softwoods in that they are all much stronger proportionally to their weights. Spotted gum and Jarrah are particularly hard wearing and very weather resistant even without finishing. Tasmanian Oak is softer and more prone to rotting and fungal attack. All of these timbers will crack and warp if left unfinished as the moisture moving in and out of the wood eventually degra...
