Bamboo is a fascinating material.
It is becoming more and more popular as a sustainable material in construction and other industries.
And for a good reason.
It’s stronger than concrete and steel and is a renewable resource.
It needs little energy to grow, prevents soil erosion, provides biomass, offers wildlife refuge, and produces a healthy food supply for both animals and humans.
Bamboo produces more oxygen than other plants and captures higher amounts of CO2.
The first harvest can be taken in 5 years, a lot faster than wood forests which typically need 25 or more years.
Harvested properly, ten percent of every plant can be taken annually without needing new plants or negatively impacting the original grove.
Why does sustainable building matter?
Globally, buildings are responsible for a huge share of energy, electricity, water and materials consumption. They account for 18% of annual global CO2c emissions.
The building sector has the greatest potential to deliver significant cuts in emissions at little or no cost.
If new technologies in construction are not adopted during this time of rapid growth, emissions could double by 2050, according to the United Nations Environment Program.
How is sustainability measured in building industry?
Sustainable building (or green building) is not a simple single issue. It consists of many factors.
Sustainable building practices and technologies are constantly evolving. A wide variety of methods is used in green and sustainable building all over the world.
The fundamental principles in green building are:
- Life cycle assessment
- Siting and structure design efficiency
- Energy efficiency
- Water efficiency
- Materials efficiency
- Indoor environmental quality enhancement
- Operations and maintenance optimization
- Waste reduction
- Reducing the impact on electricity networks
Green building means that one or more of these principles has been optimized in the construction.
With good design, individual green building technologies work together and produce a greater effect.
The common objective of green building practices is to reduce the overall impact of the constructions on human health and the environment.
The before mentioned goals can be summed up in 3 broader categories to achieve the objective:
- Efficiently using resources
- Protecting resident health and improving employee productivity
- Reducing waste, pollution and environmental degradation
Where does bamboo come into this?
Bamboo mainly goes under the sustainability of materials however it does play a role in other ways as well. For example, bamboo structures will have better air quality if compared to more toxic building materials.
Bamboo vs wood
Although bamboo that`s used in construction is woody, it is actually a grass.
Both hardwood and bamboo can be used for supporting structures in the building as well as surfaces like floors, walls, roofs.
So what are differences between bamboo and woods in terms of sustainability?
One of the most obvious differences is the speed of growth.
Bamboo can be ready for construction within 5 to 7 years. Hardwoods require at least 35 years.
The speed of growth is not the only way bamboo wins over hardwoods, though.
Bamboo can grow on marginal land, not suitable for agriculture or forestry.
On average in a span of 20 years, bamboo produces 12% more material than any woods.
Bamboo has a high elasticity. So it works as a great building material for earthquake-prone regions. It also regenerates quickly even after strong storms.
After cutting bamboo the soil is not exposed to erosion but that happens in clear-cutting of trees. The rhizome mat, which continues to live after each bamboo harvest, protects the ground from erosion.
Bamboo is relatively lightweight because the culms are hollow. So it can be harvested by hand or small chain saws. That means – less fossil fuel is used than by large machinery to harvest trees.
Stronger than steel
Bamboo may look light and fragile, but in case of this material – looks are deceiving.
Research shows the tensile strength of bamboo is 28,000 pounds per square inch. That`s more than steel which measures at 23,000 pounds per square inch.
This incredible strength comes from the fibers which make up the inner and outer skin. The skin is waterproof, thanks to high silica content.
It protects the inner wood from weather and insects. Also, the hardness of the inner wood under the skin is similar to oak.
The structure of bamboo is like a tube with reinforced joints or segments. This natural tubular design results in lighter weight over longer lengths and protects against bending and breaking much better than a steel rod.
Also unlike steel, bamboo is not a heat conductor. It is a great insulator, providing natural cooling and energy efficiency in a building.
Moso vs Guadua
Two of the most popular species of bamboo in the world for construction are:
- Guadua bamboo in America
- Moso bamboo in Asia
For purposes of architecture and construction, age and species are critical. Every country has its own preferences when it comes to species. Harvesting age, on the other hand, is fairly standard all over the world. That is – around 5 years.
Guadua bamboo (Guadua angustifolia) originates from tropical forests in the Central and South America. Guadua prefers humid habitats of cloud forests and lowland tropical jungles but can withstand cold climate.
Guadua bamboo has a very straight and strong pole, thick-walled, the average diameter is 10-17 centimeters. Guadua grows up to 21 centimeters a day. In the first 5-6 months, Guadua bamboo can reach a maximum height of 30 meters. It can be harvested after 4-5 years.
Guadua is considered to be the world’s strongest bamboo. It has extraordinary load bearing capacity.
Moso bamboo (Phyllostachys pubescens) originates from China. It has an unusual development process.
After planting, for the first 5 years, Moso bamboo doesn’t have any signs of growth. However, like a miracle, it grows up to the height of 70cm per day, even 120cm. Within 40 days, it can reach nearly the height of 30m with a diameter of culm about 18cm.
Moso bamboo is the most valuable bamboo in Asia, especially China, It is one of the most highly used plants for economic activities.
Moso bamboo is used widely in the construction, paper, textile, and wicker industries.
In disaster-prone areas, bamboo holds great potential for both temporary and long-term shelter, according to UN Habitat analysis of green building materials.
Bamboo frequently grows in climates and regions susceptible to hurricanes, typhoons, floods, and earthquakes, so shelters can be built on the spot using locally available materials and labor.
As a permanent shelter, the advantages of using bamboo in disaster-prone areas come from the lightness and flexibility of the material, which gives it resilience to collapse in strong winds.
The cost of bamboo shelters can vary greatly depending on the intended life-span of the building. Temporary shelters may be constructed for low cost, but predictably will be less stable and of lower quality.
Bamboo buildings for long-term use will be more expensive and require more time and skilled workers to construct. The payoff, however, is that the finished home will be more appropriate to the climate and culture.
Cons of bamboo
Even though bamboo is a great sustainable building material it comes with its cons.
Bamboo is widely used in construction but it is still new and not well established in many countries.
That means that bamboo may not be widely available or face regulatory problems which restrict its usage in construction.
Other cons to bamboo in construction are:
- Shrinkage: Bamboo shrinks much greater than any other type of timber especially when it loses water
- Difficulty forming secure joints and connections
- Vulnerability to fire
- Vulnerability to insects and fungus.
With proper building techniques and treatment of bamboo, these problems can be overcome.
Bamboo is used as a building material in countless beautiful homes all around the world.