The use of engineered timber in Australia is growing in popularity, and is being used in more intricate and interesting ways than ever before.

Timber Development Association (NSW) chief executive Andrew Dunn says, “We are presently on the cusp of change in the use of timber in Australia.”

There are a number of reasons for this, Dunn explains.

Firstly, the availability of sawn timber in long lengths and widths is unlikely from the current regrowth and plantation forest types.

Secondly, engineered wood products are more stable than sawn timber.

And lastly, engineered wood products are a more efficient use of wood, as more of the log is utilised in the products.

With the use of engineered wood products, the timber industry is better equipped to compete with the concrete and steel industry in residential and commercial structures due to the recent introduction of cross-laminated timber (CLT) and technology developments from Sustainable Buildings of the Future (STIC).

“Add into this the superior environmental attributes, workability and low on-site labour requirements, it’s becoming a new material that is seriously being considered by many building designers,” he says.

This can be shown through the Timber Design Awards – entrants have grown 10-fold in the 13 years the awards have been running.

“The quality of the entrants in the last few years has been outstanding. Designers are now starting to push the boundaries of wood use and it’s reflected in the awards – 2011 and 2012 were exceptional years, but what is in the pipeline for 2013 and 2014, will blow them away,” Dunn says.

The types of engineered wood products now available in Australia include:

  • Plywood: the original engineered wood product is made from sheets of cross-laminated veneer bonded under heat and pressure to make a panel.
  • Oriented Strand Board (OSB): made from strands of wood, oriented lengthwise, then arranged in layers to form a wood structural panel, which is produced in continuous mats.
  • Glued Laminated Timber (glulam): layers of dimensional timber are glued together, creating large structural timber for use as vertical columns or horizontal beams. It can be produced in curved shapes, making it highly flexible in its design.
  • Laminated Veneer Lumber (LVL): thin wood veneers are bonded together in a large billet.
  • Cross-Laminated Timber (CLT): a multi-layered panel, ideal for floors, walls or rooves.
  • I-joists: with top and bottom flanges to resist common bending stresses, I-joists are designed to carry heavy loads over long distances.

In the housing industry, Dunn says, the use of engineered timber will see a continuing steady growth. New product types are not expected to appear, but there will be a greater range of available products.

Meanwhile, in the non-housing industry and in larger scale developments there is great interest to use engineered timber, such as in residential and office construction. CLT and Laminated Veneer Lumber (LVL) will stand out. There is a large array of new systems in development that push the boundary for where wood can be used, such as in large span grid floors, rooves and highrises.

As engineered wood products are man-made they are very versatile and are available in a range of thicknesses, sizes, grades and exposure durability classifications. There are an unlimited number of applications for engineered timber.

Engineered wood products have greater structural strength than typical wood building materials and are very stable. More design options are available with engineered wood, without having to sacrifice any structural integrity.

Laminated Veneer Lumber (LVL) is made by bonding thin wood veneers together in a large billet. By aligning the grain of the veneers with the long direction of the LVL billet, the resulting product has better mechanical properties and dimensional stability that offers a bigger range of width, depth and length than conventional timber.

An example of LVL application can be seen in the Candlebark School Library in Victoria’s Macedon Ranges, designed by Paul Haar Architect, which was the overall winner at the 2012 Timber Design Awards. (pictured).

Cross-Laminated Timber (CLT) is versatile and made up of numerous panels made of lumber. Each layer of board is placed cross-wise to the adjacent layers, allowing for increased rigidity and strength. Melbourne’s Forte apartment building has been completely built out of CLT and is the world’s tallest timber building.

Other recent high profile applications of engineered wood products include the new building at Massey University’s College of Creative Arts in Wellington, NZ (LVL); The University of British Columbia’s Earth Sciences Building in Canada (CLT); and the new seven-story Tamedia office currently being built in Zurich, Switzerland (laminated wood). 

 

Massey University’s College of Creative Arts in Wellington, NZ. Image: Massey University