Building a green world
The construction industry has joined the international call to go “green”. ANLERIE DE WET looks at the rise of different eco-friendly building materials and the benefits they provide
Green building materials are becoming more and more popular in a bid to fight climate change. Although the list of green building materials includes wood – only if reforestation takes place – and bamboo – which grows back extremely fast – new technology has allowed the list to grow.
Other materials have become even more popular than the traditional wood and bamboo, as they can be renewed and recycled – and often require virtually no chemical treatment.
HempCrete is a concrete-like material made out of a mixture of hemp and lime. The hemp fibres are moulded into strong and light shapes, such as blocks. HempCrete blocks are extremely light and easy to transport, and hemp itself is a fast-growing, renewable resource.
Another green brick is made using mycelium, which is part of a fungus or fungus-like bacterial colony, such as mushrooms. Mycelium can be moulded or formed when it grows around natural materials and composites. It is then air-dried to create lightweight, strong bricks.
Adobe bricks are the closest alternative to fired bricks. They are made of mud or clay in a brick form, but instead of being fired, they are left to dry in the sun. Many fibres, such as hemp and straw, can be added to the mud or clay to increase the mechanical stability and insulation capacity of the bricks.
Panels and insulation
Kirei is made from sorghum, which is a tall millet plant. For many years the woody stalks (a waste product from millet crops) were burnt and caused air pollution. Now, the waste is being used to make Kirei boards and panels that are polished with natural balms to keep them scratch proof.
Kirei is one of the fastest-growing renewable building materials. It is non-polluting, because it doesn’t emit volatile organic compounds, or contain any formaldehyde.
Cotton insulation is made from recycled cotton, which is treated with boric acid to make it fireproof and pest resistant. It is bio-degradable, contains no formaldehyde and can be used to insulate houses and commercial buildings.
Biocomposites are developed from crop residues that make use of natural waste. The list of materials include cane, jute, banana leaves, palm leaves and kapok.
A biocomposite is usually made of several different materials bound by balms to make it renewable, biodegradable and recyclable.
Biocomposites are very popular green building materials and the number of fibres used is increasing. They are used mainly as panels, and wall and ceiling insulation, but can also be used as roof tiles, window sills and much more.
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, which is widely mined. When water is added to gypsum it creates a white paste, which is mostly used as the main element in many forms of plaster, blackboard chalk and wallboard. Gypsum can be recycled and be used as a fertilizer.
When recovered or recycled, gypsum doesn’t lose any of its original qualities and can be repeatedly used without any loss of material or function. This is very rare in any type of material.
In recent years, shipping containers have been reused to build cost-effective, eco-friendly homes, libraries, clinics and commercial properties. Structures made from shipping containers are easier and quicker to build and are greener than those built using bricks and cement.
Monolithic domes are made out of polyurethane foam, with a steel-reinforced concrete base. These domes use approximately 50-percent less energy for heating and cooling than same-size, conventionally constructed buildings.
Many construction companies have been using green building materials for decades. Thankfully, with the continous evolution of technology, natural resources can be extracted and strengthened for construction use, so more and more eco-friendly construction companies are popping up to make the world a greener place.