timber in environmentally sustainable development Timber as a Sustainable Material Timber as a Sustainable Building Material 0.0 title

timber in environmentally sustainable development Timber as a Sustainable Material Timber’s innate attractions Timber is a light, strong material, used in building structures for millennia because it is: –Renewable; –Simple to manufacture; –Easy to use; and –Stable and safe. Importantly now, it is also a store for carbon. Woolmers pump house, Tasmania, 1841

timber in environmentally sustainable development Timber as a Sustainable Material Ease of manufacture Producing timber, poles, veneer and engineered timber products is a relatively simple, low capital process. It uses few chemicals, relatively little energy, and produces few pollutants. Staff of a small veneer plant

timber in environmentally sustainable development Timber as a Sustainable Material Transport Logs weigh about 1 tonne/m 3.They are transported from the forest in trucks. Most sawmills are positioned near their log supply, so transport distances are usually not long. Logs on landing and being unloaded

timber in environmentally sustainable development Timber as a Sustainable Material Producing sawn timber Logs are delivered to site, stored and then sawn. Because of the character of logs, only about 35% of hardwood and 45% of softwood logs are converted to timber. The remainder is sawdust or chipped. Hardwood saw mills

timber in environmentally sustainable development Timber as a Sustainable Material Timber drying (or seasoning) The timber is then dried. This is either in the open air or in a kiln. Air drying is slow and very low energy. Air dried material can be finished in the kiln. Kiln drying is faster. Often, shaving and sawdust fires the boilers that heat the kilns. Timber in racks for drying

timber in environmentally sustainable development Timber as a Sustainable Material Dry milling & sale Dry timber is graded and sorted. It can then be moulded to different shapes or sold for further processing. Often, no other processes are necessary before it can be used. Quality control in a dry mill

timber in environmentally sustainable development Timber as a Sustainable Material Veneer manufacture Logs for structural or decorative veneer are delivered to site. It may be sawn into flitches and heated in water before peeling or slicing. Unused section of log are often sawn into timber. Stacking veneer from a slicer

timber in environmentally sustainable development Timber as a Sustainable Material Veneer drying and grading Once sliced or peeled, the veneer is dried in a dryer, before being graded. After grading, the veneer is trimmed and can be laid up into sheets. Grading veneer

timber in environmentally sustainable development Timber as a Sustainable Material Engineered products Plywood and LVL are layers of peeled veneer glued and pressed together in industrial equipment. Nail plating of trusses requires a simple hydraulic press and a work space. Pressing nail plates

timber in environmentally sustainable development Timber as a Sustainable Material Glue lamination Glue laminated material is sawn timber, planned to give a smooth edges and adhered with a waterproof glue. Transport is the only effective limitation on the size of glulam members Prefabricating glulam beams

timber in environmentally sustainable development Timber as a Sustainable Material Refurbishment & recycling The ease of initial manufacture translates to an ease in: –construction –refurbishment; & –recycling, Large sections, joinery and fitting are often recycled. Smaller sections may be reused.

timber in environmentally sustainable development Timber as a Sustainable Material Carbon storage in forests During photosynthesis trees absorb CO 2 from the air, stores the carbon in woody tissue and give off oxygen. To produce 1 Kg of wood, a tree: –absorb in 1.47 Kg of CO 2 ; and –returns 1.07 Kg of oxygen to the atmosphere

timber in environmentally sustainable development Timber as a Sustainable Material Carbon stored in forests In 2001, Australia's plantations and managed forests stored a net 22.7 million tonnes of carbon dioxide equivalent. So, they stored more than half of the greenhouse gases emitted by all the passenger cars in Australia that year. 50% of CO 2

timber in environmentally sustainable development Timber as a Sustainable Material Carbon stored in building When logs are converted to timber and other wood products, the carbon from the tree is stored in the products. Timber buildings are carbon stores. Bus stop, Kings Meadow, Tasmania

timber in environmentally sustainable development Timber as a Sustainable Material Current greenhouse accounting method The current greenhouse accounting method calculates decomposition of forest products using product service life pools: –Pool 1 - service life 3 years - paper products –Pool 2 - service life 10 years - pallets, palings –Pool 3 - service life 30 years - kitchen furniture –Pool 4 - service life 50 years - poles, construction materials At the end of each pool life, the carbon is assumed to return to the atmosphere. This may overestimate emission considerably.

timber in environmentally sustainable development Timber as a Sustainable Material Alternative method Establish five service life pools of 3, 10, 30, 50 and 90 years Establish three age groups within each service life pool - Young, Mid, and Old Wood products then progress through each age group with one of five alternatives: –Progress to next age pool –Leave pool and enter landfill pool –Leave pool and enter recycling pool –Leave pool and their carbon is emitted to atmosphere –Long-term storage beyond pool service life

timber in environmentally sustainable development Timber as a Sustainable Material Carbon from forest RecycleLandfill Bioenergy Atmosphere Decomposition Product to permanent storage Longer-term storage Leaves pool Young age group of pool Mid age group of pool Old age group of pool Leaves pool Alternative Method

timber in environmentally sustainable development Timber as a Sustainable Material Alternative Method The alternative method better reflects what happens to wood products. The effect on calculated emissions is shown on the following two slides.

timber in environmentally sustainable development Timber as a Sustainable Material

timber in environmentally sustainable development Timber as a Sustainable Material

timber in environmentally sustainable development Timber as a Sustainable Material Alternative Methods - Conclusion A life cycle approach, including consideration of the use of residues, storage in service, recycling and disposal to landfill has the potential to significantly decrease the contribution from wood products to Australia’s estimates of greenhouse gas emissions.

timber in environmentally sustainable development Timber as a Sustainable Material Timber impacts compared to other materials Timber is only one of a range of materials available for construction. All material have an impact and it is possible to compare their use in manufacture and use using LCA techniques. Shear connector positions in a glulam beam

timber in environmentally sustainable development Timber as a Sustainable Material Timber uses less fossil fuel to make

timber in environmentally sustainable development Timber as a Sustainable Material Timber store carbon. Others release it

timber in environmentally sustainable development Timber as a Sustainable Material Comparative Energy Use in an idealised structure where 4 materials have an equal contribution to the structure derived from “Factor 4- Doubling Wealth - Halving the Resource Use: Embodied Energy of Materials

timber in environmentally sustainable development Timber as a Sustainable Material Timber has lower embodied energy

timber in environmentally sustainable development Timber as a Sustainable Material Timber has lower ecological profile

timber in environmentally sustainable development Timber as a Sustainable Material Timber elements have lower impact Embodied energy of differing window frames

timber in environmentally sustainable development Timber as a Sustainable Material

timber in environmentally sustainable development Timber as a Sustainable Material