Contents at a Glance...
Bamboo as a Resource
Structure & Design
Harvesting & Treatment
Future Potential & Training
Existing Bamboo Species in Australia
Commercially Available Plants for Building
What Bamboo can do for You
Bamboo as a Resource
The western world, including Australia, is not yet taking the spectacularly useful bamboo plant seriously, in spite of millions being spent on research in Asia. There, bamboos feed the people, house them, grace and shade their environment, provide musical instruments, cooking and eating utensils, furniture, hunting weapons, ceremonial artefacts, carrying and storage baskets, lampshades, ropes and strings, roof tiles, hats and hundreds of other practical and spiritual uses. Accordingly, the people show great reverence for this wonderful plant, which is the fastest growing renewable resource known to man. Using modern technology, superior plywood, composite beams and paper are now being produced in Asia on a major scale.
The most useful of the bamboos are actually giant rainforest plants - huge, beautiful, powerful grasses that are so much in demand that many are becoming endangered species. These are bamboos which flower so infrequently - often only every 30 to 120 years - that seed is not available to naturally expand or maintain their population.
As an economic building material, bamboo's rate of productivity and cycle of annual harvest outstrips any other naturally growing resource. If today you plant three or four superb structural bamboo plants, then in four or five years you will have mature clumps, and in eight years you will have enough mature material to build a comfortable, low-cost house.
Most bamboos also provide tasty edible bamboo shoots as an additional vegetable every season, and can be planted as viable crop to produce fresh shoots for the market. The diversity of use and species available encourages interplanting and avoids monoculture problems.
Bamboo in Australia has unfairly acquired a reputation as an invasive, uncontrollable nuisance; it is even banned by some local Councils. Few Australians know that there are dozens of magnificent clumping bamboos, both small and large, that are very easily controlled and totally predictable in their size and ultimate growth potential. Unlike the very invasive, cold-tolerant, running bamboos, the clumping variety will not attack your neighbour's land, are easy to maintain, and are mostly superior in their utilitarian qualities.
Structure & Design
As proof of its viability, the Costa Rican Government has introduced an educational construction program, building 6,000 bamboo houses every year. Constructed of Guadua bamboo, from plantations established only eight years ago, they are designed to eliminate the often high death-toll from Costa Rica's frequent earthquakes. Unlike Bali's elegant tropical designs, Costa Rica's innovative structures are indistinguishable from conventional houses, with exterior and interior rendering supported by the superbly strong and flexible bamboo frames, giving superior insulation qualities.
Whilst simple temporary structures are easily built, permanent, strongly-built houses that comply with Council standards can be constructed if the intending builder takes the time to learn some of the necessary basic skills and procedures required. As an example, good design involves simple bracing triangulation and load-direction placement of members, together with an adequate understanding of the different joining systems available for both lightly and heavily laden columns and beams. Columns, beams and truss members need not be limited to single bamboo culms (ie, timbers), as massively strong members can be constructed using multiple culms pinned and lashed together.
The potentially good name of bamboo as a building medium for Australia has suffered greatly due to a number of failures, attributable to the builder's enthusiasm being greater than his or her knowledge and/or technical prowess. When constructing houses, the design should ensure that bamboo is never buried below ground level, irrespective of the precautions taken, and should always be used in such a way that it is protected from direct rainfall or contact with water.
With a minimum of training, it is possible to build very beautiful houses in this medium. If larger spans, involving trusses or longer beams are required, it may be necessary to have a qualified engineer prepare simple calculations and sometimes a drawing in order to obtain Council approval. Generally speaking, Councils will approve bamboo structures subject to the house plans submitted also having an engineering drawing or specification, and subject to them receiving some indication that the bamboo is of a suitable structural species that has been prepared in the correct manner. It is not a difficult obstacle to overcome. Design strengths of different species are now available.
Harvesting & Treatment
Incorrectly harvested bamboo, regardless of species will most likely not survive longer than 2-5 years. A fundamental lack of understanding of this problem has led to unnecessary frustration due to rapid deterioration of buildings. Powder beetle (Lyctid borer larvae), attracted by the high starch content of the improperly harvested bamboo, is a major problem that can mostly be avoided by: selecting superior species, harvesting at the correct time and age, and maturing the culms properly before use. A simplified formula is that culms must be at least three years old, only ever harvested in the dry season, and must be properly handled, cured and stored before being used. Secondary treatments involving the "boucherie" system of pressure-injection (now being installed at Bamboo World), or the slow method of placing freshly cut culms in buckets of Borax solution for up to two weeks, will provide an even more effective preventative.
When bamboo is exposed to heavy moisture, it is eventually destroyed by fungus, which is what happens when it is exposed to weather. With such direct exposure, the only way of preventing this would be by injecting it with chemical formulae of varying levels of environmental acceptability. Effective treatment of bamboo by soaking is not possible, because the cellular structure admits moisture primarily only in a longitudinal direction. Even slightly viscous liquids, such as thin oil, have difficulty in penetrating the cellular structure, and salt water suffers the same fate, plus it creates an increased likelihood of hydroscopic-related fungus attack. The correct procedure (of proper selection, harvesting and maturing) is simple to learn and apply, but failure to do so is costly in the long run.
Future Potential & Training
With Australia's influx of Asian people accustomed to bamboo, demand for good quality bamboo timber (ie, culms) for a diverse range of uses will increase considerably. However, our use of bamboo will be limited by our (Australian) lack of sufficient good quality, mature bamboo, our lack of architects and/or engineers trained in bamboo design, joining systems, harvesting, treatment and strength of relevant species, and of carpenters with the skills to economically and efficiently build bamboo structures.
Our goal at Bamboo World* is not only to promote and supply this beautiful, utilitarian resource, but also to train architects, engineers, tradespeople, universities and TAFE Colleges, craftspeople, home-builders and environmentalists to properly utilise superior bamboos for their many hundreds of useful purposes. The educational process must expand concurrently with the increasing availability of the resource. With rapidly decreasing and deteriorating native timber supplies, the time will come when bamboo will play an important role in Australia, particularly as a multi-purpose, cost-free, rapidly renewable material, quantities of which can be grown in quite small areas without loss of control, yet with benefit to the environment.
* See under Building - Bamboo, Nurseries, Networks & Advice, in the Alternative Directory.
Whilst superior structural clumping bamboo plants are now available in Australia, we have very limited existing resources available in our established bamboo stands. Nearly all the bamboo now growing in this country falls into one of 3 categories:
1. GOLDEN BAMBOO (Phyllostachys aurea) and BLACK BAMBOO (Phyllostachys nigra)
These two cousins, Golden being the more common, are fairly thin-walled, yet if properly harvested and treated, are very useful for light structures. Shoots are edible but inferior. These are terribly invasive, hard-to-control, running bamboos and have been largely responsible for the bad reputation that bamboo has acquired in Australia.
2. PAINTED BAMBOO (Bambusa Vulagaris cv vittata)
This is an attractive, decorative, vigorous clumper, but is a little hard to control if let go for some years. It is very high in starch, fairly thin-walled, the shoots are not edible and it is considered an inferior structural bamboo - to be avoided, if possible.
3. BALCOOA (Bambusa Balcooa)
Originally from India, is a large (to150mm diameter) clumping bamboo, widely valued in its own country for building, furniture, etc. (Balcooa's shoots are edible - they are widely eaten in India - but must be properly prepared to remove arsenic content). It is superior as a construction species to the two abovementioned types, again, subject to correct harvesting procedures. Easy to control if tended annually. This species grows throughout N-E NSW in 30-plus year-old, untidy clumps - a condition easily avoided with a little care.
(125 TO 200MM DIAMETER AND LARGER)
Bambusa Bambos (syn arundinacea) ***
Dendrocalamus asper ****
Dendrocalamus giganteus ***
Dendrocalamus latiflorus ***
Dendrocalamus atter ***
Gigantochloa pseudoarundinacea (syn G. maxima) ***
Gigantochloa robusta (syn G. verticiliata) ***
Guadua angustifolia ****
(GENERALLY 50-100MM DIAMETER)
Bambusa oldhamii ***
Bambusa tulda ***
Dendrocalamus membranaceous **
Gigantochloa ridleyi cv "Jajang"
Phyllostachys bambusoides "Madake" ***
* NB: Asterisks indicate that the species is plantation-grown. Multiple asterisks denote that the species is more highly valued than most others in its category.
Bamboo ply is made from a 100% renewable resource, which saves precious rainforest cabinet and hardwood timbers. Bamboo is a fast-growing, land-efficient plant, with excellent properties. It is an easily-harvested plantation product with incredible tensile strength.
(See Alternative Directory - Building, Bamboo - for sources).