Tapping into Ireland’s timber engineering potential
17 March 2013
Timber is a structural material that has become the focus of considerable international attention for further research and development because it is a natural renewable resource, is recyclable and is relatively inexpensive.
The material acts as a carbon store and, therefore, the promotion and extension of its use in the construction industry is of critical importance to withstand the effects of climate change. While the construction industry in Ireland is significantly reliant on concrete and steel, even for small-scale structures, timber in New Zealand is a particularly important resource. Significant developments are being made in the construction of large span and multi-storey structures using timber and engineered wood products as the primary structural elements.
New Zealand has state-of-the-art laminate veneer lumber mills on both the north and south islands, numerous glued laminated timber manufacturers and fabrication companies and, in the past year, a cross-laminated timber manufacturer has commenced production (the first in the southern hemisphere). All of these companies produce engineered wood products manufactured from New Zealand-grown Radiata pine.
The timber industry in Ireland could learn how best to advance further the use of home-grown timber in the construction industry by examining the advancements in timber engineering that have taken place in New Zealand. Several innovative buildings have recently been completed, where the latest knowledge and most recent advancements in research have been used.
The new aviation display hall at the Museum of Transport and Technology (MOTAT) in Auckland, which opened in late 2011, comprises a timber portal frame with span of 42 metres. The project was constructed using box beams manufactured from laminated veneer lumber, an engineered wood material that has the strength to compete with steel and aesthetic qualities of wood.
Post-tensioning technology for seismic design and prefabricated composite timber-concrete innovations has been used in the construction of the College of Creative Arts at the Massey University building in Wellington. The primary beams and load-bearing columns for these buildings were all manufactured from laminated veneer lumber produced in New Zealand.
Further examples of seismically designed post-tensioned timber structures using laminated veneer lumber include the Nelson Marlborough Institute of Technology Arts and Media building (South Island) and the Carterton Events Centre (North Island). Numerous elegant buildings with the primary structural frame comprising glued laminated timber elements manufactured from fast-growing Radiata pine have been constructed in New Zealand and, at present, the larger manufacturers are exporting elements for use in prestige projects in Asia and the Middle East.
LESSONS FOR IRELAND
Dr Gary Raftery recently moved from NUI Galway to the University of Auckland, New Zealand, to lecture and lead timber engineering research programmes. He is optimistic that significant advancements can be made in timber engineering in Ireland.
“Significant similarities exist between Ireland and New Zealand,” said Dr Raftery, who was heavily involved in timber engineering research in Ireland. “A single softwood species dominates the forest reserves of both countries – Radiata pine in New Zealand and Irish-grown Sitka spruce in Ireland. Both species are extremely fast-growing and generally produce lower quality timber in comparison to the timber produced in Scandinavia. Similar climatic conditions, with moist environments, are experienced by Ireland and New Zealand. Therefore, durability can be an issue.”
He added that the lessons learnt using Radiata pine in New Zealand can be followed in order to increase the use of Irish-grown Sitka spruce in the construction industry. “With the correct technical knowledge, timber and engineered wood products can be protected against problems relating to moisture and used to construct large scale timber structures in Ireland,” he continued.
“Furthermore, the environment in New Zealand poses difficulties relating to the presence of extremely harsh ultraviolet rays, which can cause localised checking and cracking of exposed timber surfaces – this can result in premature decay. This is a problem that’s not experienced on the same scale in Ireland, thus affording Ireland greater opportunity to advance further the use of fast-growing locally sourced timber in industrial, commercial and multi-unit residential structures.”
Dr Gary Raftery is currently working as a Lecturer in Timber Engineering at The University of Auckland, New Zealand. He had previously worked as an academic staff member at the National University of Ireland, Galway for three years where he was heavily involved in timber engineering research in Ireland. Gary was awarded his PhD degree from the National University of Ireland, Galway in 2010 and was a key figure in the development of the timber testing research facility at the university.http://www.engineersjournal.ie/2013/03/17/tapping-into-irelands-timber-engineering-potential/http://www.engineersjournal.ie/wp-content/uploads/2013/03/Raftery-NZ.jpeghttp://www.engineersjournal.ie/wp-content/uploads/2013/03/Raftery-NZ-300x300.jpegBioconstruction,renewables