Today, sustainable architecture is not just a trend but an architectural style that has become a "revolution." Utilizing locally available natural material is a key element in any Green Architecture approach. Bamboo, which is an extremely fast-growing species of giant grass, grows abundantly, quickly, and cheaply in Vietnam, where canes cost as little as a dollar each.
Vietnam has a tropical climate with high temperatures and humidity, advantageous for the growth of bamboo. Therefore, bamboo is an important forest resource of Vietnam. The annual consumption of bamboo in Vietnam is between 400 - 500M bamboo culms, used for various purposes. As an export crop, its value is well over 200M USD/year.
Building with Bamboo
Bamboo as a building material, with its high compressive strength and low weight, has been one of the most used building material in support of concrete. This is especially true in those locations where it is found in abundance. Bamboo is used for the construction of scaffolding, bridges, pavilions, outdoor structures and of course, houses.
There are essentially two types of bamboo used in VTN Architects’ bamboo projects — one uses bamboo that can bend to form curves and one that is straight. The bamboo that is bendable is locally called ‘Tam Vong’ (Latin name: Thyrsostachys oliveri Gamble), and the straight one is called ‘Luong’ (Latin name: Dendrocalamus barbatus).
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Most bamboos have a low resistance to biological degrading organisms and need specialized bamboo preservation techniques. A wide range of treatment methods are known to improve its durability. Without any protective treatment, most bamboo species have an average natural durability of less than 2 years. Stored under cover, untreated bamboo may last 4-7 years. Untreated bamboo, just like almost any other wood, has a high chance of being attacked by insects. Bamboo insect infestation occurs due to the presence of starch and other carbohydrates. Insects obtain their food supply from the bamboo and degrade it.
At VTN Architects, we put the bamboo into the water to speed up the aging process. So when bamboo rots, its chemical make-up changes so that insects like beetles will no longer eat the toughened bamboo. Treating bamboo in this way is the traditional knowledge of Vietnamese craftspeople, because of all of the baskets, chopsticks, and many other products they make from bamboo. Many villagers put bamboo into the water and they then use it after three to six months. We treat bamboo based on their knowledge but we add one more step—smoking. When we remove bamboo from the water the smell is not nice and the skin is very dry as the oil escapes. So we smoke it for two weeks to coat the outside and dry it out, that way we can replace the oil lost. Bamboo that is treated with this traditional Vietnamese method can protect the wood for 30 to 50 years.
When we smoke the bamboo we burn rice husks for the smoking, which contains oil. In this process, the smoke and the oil from the husks automatically bind with the bamboo. After smoking, we polish the outside of the bamboo to make it shiny. The combination of putting bamboo in water and then smoking it makes it last even longer.