Glulam project a huge success

Bhutan Trust Fund for Environmental Conservation, the world’s first conservation trust fund, has partnered with Academy Project in Paro to carry out the Glulam Project in Bhutan. A first of its kind in Bhutan, a BTFEC co-funded project is nearing its completion. Of the total cost of Nu 30,452,500, BTFEC has granted Nu 14,719,000 towards the project. The three-year, Management Board Grant, project began in 2015.

Glued laminated timber or “Glulam” is an engineered timber product that consist of two or more layers of timber (planks) of same species or similar physical properties glued together to form a structural timber product of any length, and sizes for construction purposes.

Glulam is a material that is made from suitably selected and prepared pieces of wood either in a straight or curved form, with the grain of all pieces essentially parallel to the longitudinal axis of the member.

The Academy Project in Paro has decided to adopt glulam design in the multipurpose hall. The huge infrastructure development plan sets an ideal platform for introduction of new building and construction methodologies in the country.  The Academy has introduced the Glulam technology rather than simply importing the product.

To ensure that the efforts are sustained beyond the project period: Natural Resources Development Corporation, has been the strategic partner, given their significant corporate social responsibility in terms of providing natural resources product and services to the public; the technology is been carried out on a pilot project basis with primary focus on introduction, demonstration and promotion of the Glulam Technology in the country.

With the successful implementation of this project, it is expected that other constructions specifically Dzongs, institution buildings, religious and historical structures will benefit from the technology.

The scope of Glulam in Bhutan can be expanded to the construction and maintenance of major structures like Dzongs, religious structures and public recreational buildings. As traditional Bhutanese architect is mostly timber based, timber will continue to be used in the construction and maintenance of all existing and forthcoming structures.

Increasing demand of timber for these structures will apparently come to face constraints in supply of timber in future due to factors such as scarcity of special and quality timber. Therefore, transition to engineered timber is the only viable option keeping in line with meeting the demand and maintaining traditional construction. Modern buildings are designed for energy efficiency and therefore “insulation”. Considering its insulation, aesthetic and other advantages, timber will remain a natural choice.

Various government agencies, projects and designers are looking for introduction of Glulam in Bhutan. There are many major projects such as Academy Project Paro, Construction of Wangduephodrang Dzong, Renovation of Phajoding Monastary, Construction of Pemagatshel Dzong and many others. A successful introduction of Glulam Technology will result in demand of the same in the above projects. The Academy Project in Paro has decided to adopt glulam design in the multipurpose hall. This concept if successfully executed will become a master showpiece to initiate incorporation of similar designs for future projects.

The advantage

Although, glulam is basically the same timber but they are characterized by smaller pieces of wood glued together into sizes common for solid-sawn timber and therefore substantially take advantage of the wastage, enable use of smaller and young trees that are grown at a much faster. Additionally, older trees or partially rotten timber can also be used as well.

Glulam offers the advantage of structural timbers that are much longer and larger. Depending on the size of the manufacturing unit, the limit to length and size can be according to demand and capacity to handle at the construction site. This advantage has directly demanded the Glulam structural components for constructions of bigger and spacious buildings such as Dzongs, bridges, sporting complex, resorts, halls and other historical and modern recreational structures.

By curving the timber products during the manufacturing process, a variety of architectural effects can be obtained that are impossible or very difficult with other materials including solid timber.

Structural elements can be designed with varying cross sections and length. The beam sections can be made deeper to account for increased structural requirements along any region of the beam. Similarly, arches often have varying cross sections as determined by design requirements.

Environmentally friendly- the renewability of wood, its relatively low requirement for energy during manufacture, its carbon storage capabilities, and its recyclability offer potential long-term environmental advantages over other material. Of every log that is harvested, nearly 100 percent is being utilized. As part of a structure, wood’s natural insulating properties (many times higher than steel or concrete) reduce the energy required to heat and cool the structure for its lifetime. In addition to the great environment benefits glulam timbers extend the available wood resources by using high-grade materials only where it is needed in the layup. Glulam also uses small dimension lumber to make large structural timber, utilizing logs from second and third growth forests and timber plantation, thus glulam is a “green” building material.

Laminated timber can be treated with external applications, which will make it resistant to humidity and most chemical exposure.

Because of the controlled manufacturing process (drying, grading and stiffness testing), much higher and durable quality of timber can be processed. By cutting the tress in small planks and by gluing them together, the defects such as knots are smaller and spread throughout the beam volume. Therefore, each defect is less critical compared to the sawn timber.

Accurate manufacturing reduces the need for on-site fabrication, minimizing waste and labour costs during installation. Equally important, glulam timbers are readily adapted to design changes and minor adjustments during construction. Because glulam maybe easily modified in the field to fit existing conditions, renovation projects are also simplified.

Glulam will not corrode. It also has a high resistance to chemical attack and aggressive and polluted environment.

Earthquake safety: The behavior of timber is very good against seismic forces and because Bhutan falls under critical seismic zone, it is important to consolidate on this advantage in construction.

Superior Fire Performance: Glulam has a high and predictable resistance to fire. Unlike steel and reinforced concrete it will not twist or spall in fire and, in some countries glulam beams attract lower fire insurance premiums than steelwork. When the timber burns, formation of carbon will reduce the penetration effect of fire and therefore, allow more time for safe evacuations and often saves a structure from total destruction.

The Future

The output of the project will go a long way in contributing to the fulfilment of the policy objective of the government in maintaining 60 percent of the land under forest cover for all times to come. Furthermore, it will help in drastically reducing the amount of timber wastes produced in sawmills. The project in turn assures the 100 percent utility of every log harvested. The project can provide hands-on basis for a realistic cost-benefit analysis to promote private future investment in such industries. It can also provide a forum for hands-on training and acquisition of skills and knowledge for Bhutanese entrepreneurs and workers involved from relevant European expertise.

There is no doubt that given the substantial available timber resource in the country and increasing demand for special timber, introduction of this technology along with transfer of skill and local capacity building more projects are expected to benefit from this technology

Background

The traditional Bhutanese construction consumes a lot of timber basically because the Bhutanese architect is based on timber designs. The proportion of timber used in the construction of traditional Bhutanese architectural structure far exceeds the proportions of stone or mud that are also basic materials. Prominent structures like Dzongs and Lhakhangs that are constructed in traditional architect, comprises of mostly timber components and intricate designs and finishing in timber. Most of the structural components such as columns, beams and roof structures are constructed out of special length and size of timber that have to be sourced from outside the mainstream logging industry. Figures maintained by the Forest Resources Management Division, DoFPS show that in 2013 alone a total of 423,543cfts of timber were allotted for construction and maintenance of dzongs, lhakhangs and other religious institutions.

With the passage of time and increasing demands the supply of timber is likely to become a constraint. The demand for timber is very substantial due to its diversity of use as optimal materials are not yet available easily in the country. Apart from Dzongs and religious structures, many other historical monuments scattered around the country are required by policy to be preserved and maintained in its original form and architect, and therefore the requirement of timber remains prominent.

The increasing human population and the rapid infrastructure development will accelerate the demand for timber, and the fact that timbers are sourced from natural forests necessitates for us to look into alternative building methods and adopt more efficient wood processing technologies.

Bhutan’s carefully calibrated policy directs the economic use of natural resources endowed in the ecosystems such that the vital, intangible and regenerative capacity of the ecosystem are not devitalized. The visionary leadership of our Kings has been reflected in the overall achievement of our developmental strategies, which places the need to strike a balance between the productive and protective functions of ecosystem.

Bhutan has long been a model for environmental stewardship. Its pledge to conservation and preservation of the environment is demonstrated by positive response to the global challenge posed by climate change. In addition to being one of the few countries in the world where carbon sinks are greater than green house gas emission, Bhutan declared its intention to remain carbon neutral during the UN Convention of Parties (COP 15) in Copenhagen.

The sawmilling and wood processing technologies in the country are still rudimentary relying on traditional equipment and often on hand tools for sizing and shaping the timber structures. This is not only resulting in huge wastages but also poor quality of workmanship. For instance use of power chain saws, band saws and mobile sawmills result in losses as high as 30 percent to 40 percent of the total volume. This loss is further exacerbated with the lack of technology to utilize undersized timbers and off-cuts. Lack of technological advancement in wood processing means the choice of wood and timber products is also limited. The general statement that consumers will not pay higher prices for semi-processed timber as far as cheap raw-timbers are available may not be valid, since there is already a trend of importing semi-finished timber as raw materials in few of the successful wood based industries in the country.

With rapid developmental activities taking place, the demand for forest products, particularly timber is growing every year giving enormous pressure to limited stock of timber in the forests with commercial value. However, on the other hand, there is a huge amount of wastes generated due to out-dated timber processing methods and conventional technology.

Essentially:

  • Timber wastage is high during the processing in form of sawdust and off-cuts. A study to assess recovery percentage of timbers for different wood processing technologies in Bhutan show that 99% of sawmills, do not have the required modern technology to reduce and make use of the wastes. Furthermore continued use of conventional sawing technologies like band saw, mobile sawmills and power chainsaws have recorded losses as high as 30 to 40 percent.
  • Traditional structures constructed mainly of natural timber without any form of treatment and processing are easily susceptible to damage, thus entailing frequent replacement;
  • Lack of know-how and technology to process timber from young trees and utilize undersized timber results in harvesting of old matured trees and huge wastages;
  • With the growth in the number of constructions every year, the supply of timber is not able to meet the demands, thus leading to a huge rise in the cost of the timbers. When the timbers become expensive and there are no other readily available construction materials, the shortage also leads to black-market fuelling rampant unsustainable harvesting of forest resources.
  • Timber for the constructions of massive structure like Dzongs and bridges require longer beams and larger pillars which are now getting difficult to manage due to scarcity in nearby places and involves substantial amount of man power and cost. Solid columns come most commonly with rotting of the centre (heart) core and eventually extending out. This damage will result in severe radial cracks. Differential seasoning will also result in crack on the surface, which are often quite deep and would require remedy incurring further cost and time.

The Royal Academy project

The Royal Academy Project, a premier education campus in the country will be constructed at Pangbisa, Paro. The Academy will enhance His Majesty’s vision of supporting distinguished students from around the country in their education and leadership ultimately to groom a dynamic future generation citizens. The multipurpose hall of this facility is a modern “state of the art” building, length 77.65m x breadth 39.45m housing an indoor sports hall of 60.00m x 27.00m. The building includes separate gymnasium, other indoor sports halls, services and adequate viewing gallery. This magnificent engineering structure is designed and foreseen to be constructed using glulam supporting the entire roof and ceiling structure. Besides the MPH, other structures like the Main Academic Block, and the Dining Hall will also benefit from the current set of plants in a very significant way.

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