While many associate bamboo with musical instruments and panda food, it has long been used as a sustainable and durable building material throughout Asia, the Pacific Islands and both Central and South America. Bamboo is one of the fastest-growing plants in the world (with some species growing up to 35 inches (89cm) within a 24-hour time period!), together with having a higher compressive strength than wood, brick or concrete, and a tensile strength on par with steel. In a world where deforestation is a major environmental issue, the traditional building methods of bamboo construction may be one of the most practical green solutions available.
The History of Bamboo Construction
Bamboo has been used for centuries as a building material, traditionally to construct bridges, scaffolding and housing. The nipa hut in the Philippines is one example of a basic bamboo housing structure, with bamboo poles used to support the structure and the walls composed of split and woven bamboo, while in China there’s evidence of bamboo-built bridges having stood since at least the 10th century. In Japan, where wood is readily available for building, bamboo has traditionally functioned more as a decorative element and used to create gutters, fencing and fountains.
How to Build with Bamboo
Bamboo can be used for such a huge variety of building purposes, including supporting columns, interior and exterior walls, flooring and kitchen/bathroom fittings, as well as structural frames, corner posts, rafters and roofing. It can easily be trained into different shapes, creating a versatile material for different building purposes. For example, compressing the stalk as it grows within a square form can result in squared sections of bamboo, while arches can be created by encouraging the stalk to grow into the desired shape, either using structural constraints or heat. It can also be cut into thin strips, flattened, then boiled and dried to create laminated sheets and planks, one form that is currently seeing a huge surge in popularity, not only in China and Japan (which have honed this method throughout history), but also in the Western world.
When harvesting bamboo, it’s important that it is cut at the right time, when the culms are at their greatest strength and sugar levels in the sap are low to minimize infestation by insects. Because photosynthesis is at its peak in the middle of the day and high sugar levels are produced in the sap, many believe that dawn or dusk on a waning moon is the ideal time.
Bamboo is susceptible to the detrimental impacts of not only insects, but also rot, fungi and fire, so it does need to be treated both inside and out. Most commonly this is done using a mixture of borax and boric acid, which is applied as a chemical coating, or otherwise the bamboo will need to be replaced every 2 to 3 years. The starchy material that attracts insects within bamboo can also be removed to reduce infestations or it can be treated by heating in a kiln or over a smoking fire. It’s also important that once cut and treated, bamboo poles are stored horizontally to prevent bending or sagging with in a dry, shaded and well-cooled area, at least 50 centimeters off the gourd to encourage air circulation.
What are the Advantages of Bamboo Construction?
The regeneration rate of bamboo is one of its strongest advantages as a building material, growing far faster than trees. Most trees can only be harvested every 25-50 years, while bamboo can be harvested every 3-6 years, depending on the species. This could have a huge impact on deforestation, giving timber forests the opportunity to regenerate in the future.
Bamboo is also water-resistant, reducing the risk of warping, and both flexible and lightweight to work with. Because it can easily be grown and harvested, it’s also a cost-effective building material, making it an affordable option when compared to wood. The large leaf surface area of bamboo means that they are efficient in generating oxygen and releasing it into the atmosphere, while at the same time absorbing more carbon dioxide than trees. They don’t require fertilizers or pesticides for growth, and their extensive root system helps to draw in and store water, reducing the impacts of soil erosion.
In addition to its practical benefits as a building material, the aesthetic beauty of bamboo should not be overlooked either, with impressive results when left exposed.
What are the Challenges of Building with Bamboo?
One of the main challenges of bamboo construction is its distribution, with bamboo thriving in tropical regions (where it grows into larger diameter canes) and needing to be transported long distances for those living in cooler climates. It is possible for bamboo to be grown in other climates, but to maintain a successful and viable bamboo source that can thrive throughout the year, it needs to be grown in conditions that replicate its natural distribution.
The strength of bamboo largely comes from its integral structure, which means that it cannot be joined used many of the techniques we have traditionally come to know in building using wood. Because of this, the traditional methods of building with bamboo are particularly useful in ensuring its strength is retained and it’s important that these are shared across the world to help guide bamboo construction in regions where it has not historically been used. Over time, these ancient techniques can be combined with new methods of joinery that take into account how bamboo materials hold up in non-tropical climates.
The recent surge in popularity of bamboo construction is a promising sign for sustainable building and the experimentation with the growth of bamboo outside of its traditional distribution (including a project being conducted in the Mississippi Delta) could only enhance this. It’s not only a green solution for the developed world, but a low-cost, readily-available resource in many regions of the developing world where modern building materials are scarce and expensive. As global wood resources continue to decline, bamboo housing construction is one practical option to look towards, drawing on ancient building traditions to create a modern housing solution with aesthetically appealing results.