Mr. Small

Eco-Friendly Practices

Ancient Solution to Many Modern Problems: Structural Bamboo

By Sam Small, Vice President - Developing Markets, Bamboo Living

There's a catch-22 built into a lot of post-hurricane reconstruction efforts: Concrete is one of the most prevalent construction materials used to rebuild in hurricane zones, especially in the Caribbean. Unfortunately, concrete is a very energy intensive substance, which requires the burning of a lot of extra coal, which adds greatly to the carbon dioxide in the atmosphere, which furthers global warming, which is making for stronger hurricanes.

And let's face it; most concrete construction is downright ugly.

The fact is that pouring concrete, manufacturing steel and processing hardwoods are all much more carbon gas generating than utilizing the fastest growing natural building material in the world - Structural Bamboo.

We know all this through of a global study done at Eindhoven University of Technology in the Netherlands that compared the embodied energy of bamboo against other building materials. Embodied energy is the sum of all energy inputs required to grow, mine or extract the raw material, process the material and place it in construction, the whole nine yards relating to energy. The study found that even when you include the shipping of bamboo between hemispheres on diesel fueled cargo ships, there is ten times more energy consumed in building with concrete than in building with Structural Bamboo. According to the study too, steel and wood also have very high levels of embodied energy compared to Structural Bamboo.

To its credit too, architectural designs expressed through Structural Bamboo result in an esthetic that seems universally appealing to human occupation. Put simply, people like Bamboo.

The Most Ancient Building Material

The Chinese Academy of Sciences correlates the use of bamboo as construction material with the end of the Stone Age and the beginning of agriculture and animal husbandry in the Neolithic Age about 8,000 years ago. Ancient tales tell how the traditional architecture's inverted "V" roof was inspired by the way rain rolls down the back of a sitting dog and the up-curved ends of the roofline came through divine inspiration when The Deity transformed into a Phoenix and spread it's wings.

Modern Day Processing

Structural Bamboo has been brought into the modern age by Maui-based Bamboo Technologies. In conjunction with the International Bamboo Foundation, the Environmental Bamboo Foundation, and The International Network for Bamboo and Rattan, Bamboo Technologies modernized an ancient process using a pressure and vacuum chamber and a simple borate (salt) solution. The borate permeates the bamboo and is unpalatable to beetles and termites that would otherwise love nothing better than to feast on the sugars and starch in untreated bamboo.

With proper protection from the elements, using a marine grade varnish, the same as wood requires, the borate does not leach out over time and the Structural Bamboo has a useful life expectancy as long as any commercially available building material. By way of example, there's an entire properly protected bamboo village in Belgaum in southwestern India built in the 12th century that stands intact today.

Modern Day Testing

Standards were developed to grade and rate the treated poles. Strength and wear tests preformed at the wood materials laboratories of The University of Hawaii and Washington State University showed that bamboo's long fibers and round, thick-walled, hollow-core form make for a relatively lightweight, yet extremely durable and strong building material. Structural Bamboo exceeded 14,000 psi in tension, comparable in strength to mild steel! And by many measures Structural Bamboo outperformed Douglas Fir and concrete as well.

Modern Day Construction Material

All of this research and testing bore fruit when, in 2004, the Structural Bamboo poles as produced by Bamboo Technologies were certified by The International Code Council (ICC) as complying with International Building Code (IBC), International residential Code (IRC) and Uniform Building Code (UBC) standards. This opened the door for the use of Structural Bamboo by architects and builders in modern building code approved residential homes and many commercial structures anywhere in the world.

Bamboo Technologies also pioneered several methods of joining bamboo poles together to deliver complex structural elements and trusses that allow a wide range of elaborate architectural designs for a variety of high stress applications. (More on that in a moment when we talk more about hurricanes.)

Getting Back to Carbon Foot Printing

Like most plants on earth, during photosynthesis bamboo absorbs carbon dioxide from the air. According to the Environmental Bamboo Foundation, bamboo can sequester 60 tons of carbon dioxide/acre/year compared to 12 tons/acre/year for a tree forest. Also, bamboo generates up to 35% more oxygen than an equivalent stand of trees.

Bamboo compares favorably to all other building material, organic or otherwise, because the CO2 that bamboo takes in is eventually expelled as microscopic, carbon-rich pellets or Plant Stones that drop from the plant and layer into the leaves that litter the bamboo forest floor.

Plant Stones

Plant Stones, recently analyzed in depth by soil scientists at The Southern Cross University, are carbon deposits encased in silica and are virtually indestructible. Even if the bamboo forest is clear-cut, as long as the layers of leaves and carbon pellets are left in place and not burned the Plant Stones will stay intact for thousands of years. So growing and using Structural Bamboo for construction not only stops Carbon from entering the atmosphere it actually removes it.

Ancient Solution to a Modern Problem

Growing enough bamboo to meet the construction needs of a growing world population could sequester enough CO2 that it could help reverse the effects that excess greenhouse gasses are having on global warming. Fortunately bamboo, technically a grass, is one of the fastest growing plants on the planet. In established plantations, the bamboo culms cut for construction take only three to five years to re-grow (as opposed to 25 years for Douglas Fir) so bamboo is justifiably considered a rapidly renewable resource under the Leadership in Energy and Environmental Design (LEED) program for sustainable construction developed by the U.S. Green Building Council.

Hurricane and Earthquake Strong Designs

Bamboo Technologies has developed technical and real life expertise in bamboo construction since it started all this over fourteen years ago. To bring to market the first and still only building-code certified Structural Bamboo buildings in the USA, Bamboo Technologies developed and tested a construction system that plays off the natural strengths of Structural Bamboo to manufacture very strong buildings and allow for straightforward analysis by structural engineers.

The system uses certified bamboo poles to prefabricate finished bamboo structural panels. The finished panels allow for rapid onsite erection of the structures and ease shipping to assembly sites around the world.

Many of the structural panels serve as single and double member trusses with bamboo struts and steel joint connectors built in. Vertical truss elements in the walls with the bamboo struts and steel connectors tie together to withstand the lateral forces exerted by high winds. The main roof trusses have ridge trusses between them to resist longitudinal forces on the roofs. On the larger buildings additional trusses are added between the mains at the top of the walls to transfer forces to the vertical elements in the walls. These vertical trusses are then anchored to the foundation.

Exceptional Performance

Bamboo Technologies' factory in Vietnam built several cottages for assembly at a resort on Rarotonga in the Cook Islands off New Zealand. Structural engineers rated the buildings' design to withstand a wind load of 80 mph. In fact, in 2005, the buildings withstood winds measured at 173 mph in three separate hurricanes.

In addition to the hurricane winds the storm surge threw a large coral boulder through the end wall of one of the buildings, shattering glass, destroying a door, and shearing some bolts. The prefabricated panels themselves remained intact and the building repair required simply re-drilling and bolting the panels back together.

Hurricanes impose tremendous forces on a building; doubling the wind speed quadruples the force exerted on the structure. Bamboo Technologies is currently building homes for the Caribbean that have been engineered with a design wind load of 150 mph.

Based on the performance on Rarotonga, there's a safety margin of nearly 100% between the design wind speed and the actual wind the buildings can handle. If a design wind speed of 80mph produces buildings that withstand 173mph winds then the bamboo buildings engineered to meet the 150mph design wind speeds should perform exceptionally well in even more extreme hurricane conditions.

Three Solutions in One

Structural Bamboo is an exceptional answer to the Catch 22 of post hurricane building techniques, like poured concrete, that are essentially ugly and in the long run increase carbon gas emissions that in turn create stronger and more damaging hurricanes.

Not only is Bamboo beautiful and comfortable to be around, it's utilization stops the outpouring of CO2 from concrete use and the growing of bamboo actually sucks greenhouse gasses from the atmosphere and sequesters the carbon indefinitely.

Bamboo Technologies' innovative designs afford an extraordinary opportunity to survive the mega hurricanes that could be coming to many regions and better yet, the wide spread growing of bamboo itself could end up saving the regions from the disastrous winds altogether. That's the reverse of a Catch 22, that's a Win/Win!

Sam Small is VP of Developing Markets with Bamboo Living, based in Maui, HI. After a successful career in mass media Sam Small has turned his sights towards promoting Bamboo as a sustainable and globally appropriate construction material. Originally a customer of Bamboo Living, Sam was so impressed with the product and the company that he became directly involved. He has so far supervised the assembly and finishing of three bamboo structures, and currently lives in a bamboo house on Maui. Mr. Small can be contacted at 973-271-0788 or sam@bambooliving.com Extended Bio...

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