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| Source: https://countrylumber.ca/engineered-wood |
This article is a continuation of my previous article posted on 28 December 2017, which argued why wood is a better choice than other building materials, such as concrete and steel, from an environmental point of view. This article then moves on to examine the untapped potential of engineered timber products in the construction of multi-storey modular buildings and even skyscrapers, particularly in the Malaysian building sector.
Building Taller and Bigger with Engineered Wood
Although we are urbanizing at an alarming rate and building higher is becoming a necessity, we are reluctant to consider using wood in constructing buildings of more than four stories. We urgently need to start to consider constructing medium-rise and even high-rise buildings out of wood, particularly engineered wood products (also known as composite wood). Using timber as a structural member has traditionally been limited by the sizes of the timber logs available, which, in turn, were restricted by the practicalities of its handling. With engineered wood, many of these problems can be overcome and we can now create spans and structures using timber, which would have been impossible only 20 to 30 years ago.
Examples of engineered wood products are glue-laminated (or glulam) posts and beams and cross-laminated timber (CLT) panels. Glulam was first used in Europe in the early 1890s. It is a structural timber product manufactured by glueing together individual pieces of dimensioned and strength-graded timber using durable, moisture-resistant structural adhesives. It is ideal for load-bearing structures where long spans are desired. It also offers the architect the freedom of artistic innovation without structural constraints.
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| Figure 1: Cross-laminated timber (CLT) |
CLT was pioneered in Europe in the 1990s to replace concrete blocks in the construction of family homes. CLT is produced by pressure-glueing multiple layers of lumber boards placed perpendicular to one another, giving the wood steel-like strength (Figure 1). CLT is made of panels that are enormous (8 feet wide x 64 feet long) and of various thicknesses; hence, they are called mass timber panels. These panels can be practically used for load-bearing walls, roofs and floors, and they can be used to replace precast concrete in Industrialized Building Systems (IBS). CLT has the advantage of reducing construction time and labour costs. In terms of fire resistance, CLT panels are hard to ignite, and when they do, they actually burn at a very predictable rate, giving occupants more time to escape. When CLT catches fire, it chars only on the surface instead of burning right through.
The concept behind engineered wood production is to produce large timber products from small timber elements, which is a sustainable way to use timber. The advantage of engineered wood is it requires less mature trees and avoids the need to harvest old and strong trees from the thick forest (Minler, 2009).
In 2014, Architect Michael Green completed a 6-storey CLT building in Prince George, British Columbia, known as the Wood Innovation Design Centre. It serves to showcase the potential for building mid-rise and high-rise structures using engineered mass timber products. There is no concrete used in the building above the ground floor slab. The design incorporates a simple, 'dry' structure of systems-integrated CLT floor panels, glulam columns and beams, and mass timber walls.
A year later, the 8-storey Puukuokka Housing Block was built and it is currently the tallest wooden apartment block in Finland and one of the first CLT medium-rise buildings in the world. In the same year, Hawkins\Brown Architects completed a 10-storey apartment block in London, called The Cube. It is constructed using a hybrid structure that is primarily CLT but also integrates steel elements and a reinforced-concrete core. Currently, the world's tallest building built using CLT is the 18-storey-high Brock Commons Tallwood House (student residence) at the University of British Columbia in Vancouver, Canada. Built in less than 70 days, the design incorporates a hybrid structure of CLT floors, glulam columns, a concrete base, and two concrete cores.
With regards to the construction of tall wooden buildings, Asia is probably a thousand years ahead as it has the 56-metre high (excluding the spire) Sakyamuni Pagoda that was built in 1056 in Yingxian province and has survived numerous fires and earthquakes over the years. Excluding Australia, Singapore will soon boast Asia's first and largest engineered wood building, built using materials taken from renewable forests and prefabricated for on-site installation. This new 40,0000 square-metre business school academic building at Nanyang Technological University (NTU) is expected to be completed in 2021. This project has only been made possible thanks to the far-sighted decision to overturn a previous ban on the use of structural timber in Singapore under the revised January 2013 fire codes (Hill, 2015).
Current Timber Construction Scenario in Malaysia
Malaysia is one of the main producers of the world's good quality timbers that are in very high demand all over the globe. However, it is unfortunate that the country does not fully utilize its rich timber resources in the field of engineering in general, and as structural materials in particular, in contrast with developed countries. Jumaat et al. (2006) lamented that the interest in using timber as a structural member in the country is almost non-existent. Timber is mainly used for non-structural elements such as formworks, panelling and partitions. In the last few decades, the industry has increasingly used other alternative materials such as bricks and concrete (Abu Hasan et al., 2011).
In line with this realisation, the Malaysian Timber Industry Board (MTIB), as the government agency responsible for the overall development of the timber industry, has taken steps to encourage the use of timber in construction. For example, in 2011, the MTIB took the initiative to establish the Galeri Glulam in Johor Bharu, the first completed building in the country that uses glulam beams for its main structure (MTIB, 2017). As a showcase and referral centre for professionals and government and private agencies in Malaysia, 80% of this 3,700 square-metre building was constructed from two Malaysian hardwoods - Resak and Keruing - and promoted the use of locally produced glulam in construction. Around the same period, The Crops for the Future Research Centre, a joint venture between the Malaysian Government and the University of Nottingham, was built in Semenyih. A total of 200 square metres of glulam made of Malagangai timber was used for its three domes.
In addition to the above, several other buildings in Malaysia have used glulam in their construction, but these have been relatively small-scale and low-rise. Furthermore, the use of CLT in Malaysia is still in its infancy, with only a few studies having been carried out by the Forest Research Institute Malaysia (FRIM). There are almost no reports on the utilisation of engineered wood in the construction of large or tall structures in Malaysia, where the use of wood as a principal construction material has not increased, despite the advertisement and promotional campaigns by the MTIB.
Although historically, wood has been used as the principal material in their vernacular architecture, in recent times, Malaysian architects have designed fewer and fewer buildings using wood. The reason for this is as follows: the relatively high cost of wood, a negative perception regarding its durability, and continued concerns over its structural performance and fire rating.
Future Directions
Constructing high-rises, commercial buildings and residential towers completely from timber, or engineered wood is rapidly gaining popularity internationally, and Malaysia is in danger of being left behind. Singapore's proposed building at NTU is not radical, but it will be the first of its kind to be introduced to the Southeast Asian region and may become a game-changer. Meanwhile, mainstream acceptance of engineered wood in Malaysia remains a long way off. There are currently no benefits of economies of scale; therefore, mass-engineered timber projects will likely remain expensive in the foreseeable future.
The following actions are recommended to increase the demand for engineered wood in building construction and to achieve the required economies of scale:
- Conduct more rigorous research and testing to commercialise the positive attributes of wood and boost confidence in the utilisation of wood in construction. This is particularly important considering the diversity in the tropical hardwood resources and the growing importance of lesser-known timber species. Research done would enable builders to utilise non-structural grade timber and lesser-known species in structural components. This would also reduce the dependency on high-grade commercial timbers, which are decreasing in numbers. As such, efforts by the MTIB in undertaking R&D programs in collaboration with local universities and research institutes should not only continue but also be intensified with more involvement from more experienced international experts.
- Revisit the existing building regulations and building by-laws in responding to research data and findings to encourage the wider use of wood and wood products in building construction. It will also be important to receive the support of all related government agencies and regulators.
- Promote and inculcate knowledge of timber architecture and engineering design through formal education (e.g. courses in universities) and informal education (e.g. seminars, training, and conferences).
- Continuously disseminate information about wood and wood products to the general public through mass media to increase their awareness and allay any fears and misconceptions about building with wood.
In conclusion, the question that remains unanswered is whether wood buildings can ever be constructed as tall as modern skyscrapers. However, the greatest challenge is not overcoming the engineering obstacles to achieving the above but challenging the perception of the potential of timber in modern construction. Only four years after the completion of the 10-storey Home Insurance Building in Chicago, technically the world's first skyscraper, the Eiffel Tower, equivalent to an 81-storey building, was built in Paris. Subsequently, places like New York City and Chicago started to compete by building bigger buildings and pushing the envelope higher with better engineering and the skylines of cities worldwide were changed forever.
Therefore, we should view our current predicament as an opportunity to create another Eiffel Tower moment. As the construction of engineered wood buildings increases worldwide, concerns over their limitations and structural integrity will dissolve and become increasingly common. With a concerted effort from all interested parties to remove the obstacles and change mindsets, we may yet one day find a prominent and elegant engineered wood building standing proudly in one of Malaysia's city centres.
As Australian architect Alex de Rijke (de Rijke, 2015) said, "The 18th century was about brick, the 19th about steel, the 20th about concrete, and the 21st century is about engineered wood." So, the following is a message to all developers, architects and engineers: if you cut down a tree to turn it into something, honour that tree's life and make it as beautiful as you possibly can.
References
Abu Hasan, A.B., Mahyuddin, R., Jamaludin, M. and Adamy, A. (2011). Awareness assessment framework for implementing the sustainable housing in Malaysia, Asian Journal of Management Research, Vol. 1: 703-713.
de Rijke, A. (2015). CLT will be considered conventional in Australia by 2020.
Hill, K. (2015). The unlocked potential for engineered wood structures in Asia, Panels & Furniture Asia, May/June, Issue 3: 50-53.
Malaysian Timber Industry Board (MTIB) (2017). Gallery Glulam.
Baker, F. M., & Lightfoot, O. B. (1993). Psychiatric care of ethnic elders. In A. C. Gaw (Ed.), Culture, ethnicity, and mental illness (pp. 517-552). Washington DC: American Psychiatric Press.
Author's Note:
This article is published as the second half of a chapter in a book titled "Greening Malaysia" by Pertubuhan Arkitek Malaysia (PAM).
For full citation: Shari, Z. (2017). Why Not Wood: A Case Engineered Timber Construction in Malaysia. In M. Gelber, B.C. Wee, S. Hijjas (Eds.), Greening Malaysia (pp.254-263). Kuala Lumpur: Pertubuhan Arkitek Malaysia (PAM).
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