From innovate treatments that improve the durability of timber and timber products, to new products designed for specific applications and connections that reduce assembly time and costs, this is an invaluable resource.View
Massive timber systems Die Brettstapelbauweise
This version of Brettstapel uses massive timber plate elements which are premanufactured automatically by mostly using aluminium nails to hold boards together. Other manufacturers in the market place may alternatively use low moisture content dowels placed as an alternative system for connecting the boards together – the dowels are inserted with a very low moisture content and then expand insitu (to equilibrium moisture content), thus creating a friction based means of holding the boards together. Under either scenario, no glue is used, thus neutralisng concerns with off gassing associated with competing glued systems. The wall elements are between 80 and 120 mm thick and the floor elements between 120 and 250 mm. Panels are typically 600mm wide and span in a one way system that can achieve spans up to 7.0m. Furthermore, the elements can easily be combined with concrete to create combined timber-concrete floors to reach larger spans, with improved noise insulation and fire resistance. The elements can be sanded for wall or floor finishing. In Germany there are about 10 manufacturers prefabricating these type of elements.
Large floor and wall elements can be built up from simple beams. In combination with concrete, a floor can perform very well at sound reduction. Low-grad material can be used. In addition, this system:
- Locks up a lot of carbon in the massive timber floor structure, therefore providing strong environmental credentials
- Seems well suited to panelised construction up to three levels.
- Good thermal properties claimed.
In floor and wall elements there are no spaces to cater for running service pipes etc. although these can be machined in as part of the manufacturing process if necessary. Also because of swelling and shrinking of the members, potential shrinkage gaps can develop. Though new to Australia, this technology is not new in Europe. It involves structural over-use of timber whilst more recent technologies make better structural use of timber.
Cost of this system may be an issue in single family dwellings where acoustic etc performance is less of a criteria. It is most likely best applie dt multi-unit residential. Also, the ability to locate air-conditioning and heating ducts would need to be addressed. The simple use of nails to laminate appeals. Currently the system is made up using Spruce and Fir. Good randomisation of defects could allow more effective structural use of low grade sawn Radiata pine. Fire performance requires further investigation.
Structurecraft are a contractor specialising in the engineering, design detailing, supply and fabrication of complex, large and challenging timber structures. Though there is nothing especially groundbreaking about the panelized systems that they use, they occupy a worthwhile link in the supply chain that largely does not currently exist...