Tuesday, 4 May 2010

Sustainable Materials

Homes devour great quantities of materials, both in construction and in surfaces and finishes. Choosing materials with sound eco-credentials helps to minimize the harm done to our planet. There are some materials that represent good green alternatives - simple substitutions for more familiar and, ecologically speaking, more contentious versions.
When it comes to choosing materials responsibly, sustainability is a key concept. It means selecting materials that do not deplete natural resources, do not damage ecosystems and do not pose  a problem for future generations. Another factor that comes into the equation is embodied energy. Our homes use energy directly for heating, cooling and power. But materials represent energy in an embodied form - the energy that was required to extract them, transport them, process them, deliver them and work with them. The less a material has to be worked before it is used, and the shorter distance it has to travel, the lower its embodied energy

Alternatives to wood
Properly sourced from approved sustainably managed plantations, and in solid rather than composite form, wood is a good green material. It doesn't require much in the way of processing and it derives from a living renewable source. Furthermore it lends itself to both salvage and recycling. Properly maintained, a solid wood surface, or a wood with a thick veneer that can be resanded, will last for years.

Reasons to consider wood alternatives
  • Demand for construction timber far outstrips supply. While international bodies are getting better at monitoring forestry projects, in many circumstances it is difficult to be absolutely sure that a particular batch of wood has come from an approved source
  • Softwoods, which are the mainstay of the building industry, require protection from fire, moisture and pests, which is generally delivered in the form of chemical treatment. Eco fnishing treatments include borax, which is used as a wood preservative, natural waxes, oils and stains
  • In construction, new manufactured wood products such as parallam and glulam - piles of wood glued and laminated under high pressure to produce structural members capable of spanning great distances - are increasingly a preferred eco option. But when it comes to surfaces and finishes, there are a number of alternatives that look and perform just as well as wood
bamboo
Ecologically speaking, bamboo is something of a wonder plant. A woody grass rather than a tree, it is incerdibly fast growing and fast spreading, achieving a height of 1.5m within months and full maturity at 5 to 6 years. Its cultivation requires little human intervention and it does not require fertilization or the application of pesticides. Bamboo improves poor soil, cuts down carbon dioxide emissions and is fully renewable.
There are 1,500 species of bamboo, but most of the bamboo used in the production of bamboo products comes from China and Indonesia The associated transport costs mean that in this sense bamboo is high in terms of embodied energy,. but its other credentials weigh heavily in the balance.
Strands or strips of bamboo can be laminated into boards, planks, panels and veneers. Other uses include textiles and papers. The best bamboo comes from manufacturers who control the process from harvest to end product and who are able to guarantee that only a small proportion of formaldehyde is usedin the laminating process. Harvested too early, bamboo can be as soft as fir. Mature bamboo, however, is harder than maple and oak.

Characteristics
  • Renewable, plentiful resource that is fast growing
  • Strips or strands are laminated into a variety of products, including flooring-grade boards and planks, veneers
  • Different degree of hardness are available, with the toughest surpassing maple and oak in strength and durability.
  • Boards and panels are available in different dimensions and with matching finishing details, such as mouldings and trim
  • Very stable
  • Available in verticle grain, flat grain and a mixture of the two, which increaces strength, hardness and stability
  • A variety of woody colours from pale to dark shades. Some types of bamboo flooring feature natual colour variation that makes for a lively surface


 

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