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Ecological Materials

ecological trees Ecological materials are materials that don't cost the earth to produce, transport and use. For instance, using locally grown wood removes the high transportation costs of imported wood and woodlands are easily renewable. Natural timber preservatives can be made from the local trees and building boarding can be formed using steam instead of using highly toxic, formaldehyde glues. Roof tiles can be made from local clay. Different, low-impact building techniques are suitable in different geographical areas.

Cement

Cement, the principle ingredient of concrete, is made from quarried, powdered stone in areas where the underlying rocks are suitable. It is combined with other materials, such as powdered clay brought from a clay producing area, mixed, heated then transported along our roads to where-ever it is required and thus costing much in energy, transport and adding to the traffic and air pollution. Once a hillside has been removed it is not renewable. We shouldn't stop using concrete, after all it is useful, but if there are usable local alternatives we should consider different techniques to build our houses.

Concrete is difficult to recycle. It can only be crushed and used as hardcore. However, the production energy cost of a cubic metre of concrete is around 700kW/h.

Benefits of recycling

Many materials are expensive to produce:

(costs are for comparison only and in 1000s of kW/h per tonne. Courtesy of Pat Borer, CAT)

Glass (23)
Plastics (47)
Aluminium (75)
Steel (103)
Copper (133)

All are reusable and recycling greatly reduces the initial production costs.

Planting and harvesting trees

sculpted bed by Tim Stead workshop Locally grown timber is a natural, nonpolluting source of building material providing it isn't soaked in toxic chemicals.

Different wood has different qualities. Larch, Oak, Elm, Sweet Chestnut are noted for their resistance to rot and fungal attack so are useful outside. Softwoods such as pine, deal, birch and beech are useful inside the house. (Sculpted 4-poster bed by the Tim Stead workshop, Scottish Borders, UK.)

Petrochemicals should be avoided. Sources are finite. Refining and using them is extremely polluting. They can't be safely recycled once used. Use natural paints made from powdered earths and natural binders - and suitable timber.

Timber

Timber is without a doubt the best building material available - not only structurally but also exposed inside the building. Have a wood kitchen built, use wood flooring, hard-wood stairs. There are many local woods wherever you live that are very attractive.

Maple and sycamore make good hard floors. Oak is the king of timbers and so is ash and elm and all three make beautiful furniture.

Local stone

Local stone is a suitable material for the lower level of any building. It is also useful as a thermal store to store heat during the day from passive solar heating and give it off at night as outside temperatures fall. Thermal storage lessens the temperature fluctuations in a space that you get if there is little or no thermal mass and if the heat is obtained from passive solar heating then it is free.

Boarding

Boarding is used as one of the skins of walls and floors. It is structural in that it helps to strengthen the building. Modern chip and particle boards are made using highly toxic formaldehyde but there is a board made using heat and steam only to use the natural adhesive qualities of the timber chips themselves.

Paints and varnishes

Paints and varnishes are used a lot inside a house so great care should be exercised to choose nontoxic ones as they can give off gasses for months after being applied. Generally, natural dyes, colour pigments and natural resins should be used. It is quite possible to make a paint using milk, ground pigment and natural resin. I make it and use it on some of my hand-made Windsor chairs. Our grandparents did and it looks good and ages naturally producing beautiful colorations that modern paints can't achieve. It is nontoxic and therefore safer than modern paints if you have young children.

Glass

Glass is made from the most abundant material on earth - sand. It is used for windows but can also be used for roof tiles and conservatory roof as well as walls. It does conduct heat well so it loses some during the nights but it does let a lot more heat and light in during the day. Glass is inert and useful for cooking utensils and storage as well. It is recycleable.

Roof

Roof tiles can be made of local clay, slate tiles or sheet metals. When I lived at Findhorn they used both copper and zinc sheets as roof materials. The rain-water run-off from these materials can contain small amounts of dissolved metals so the run-off water has limited use for garden irrigation but it is not as toxic as the run-off from a leaded roof. Copper looks attractive after a layer of verdigree has formed and of course it is recyclable.

The most green and traditional (long-term) roof is made from turf. The roof pitch angle must be low for turf to stay on the roof but if done well turf will last for many years and can be seeded with rare plants. (Birds will do a lot of seeding for you.) Turf insulates against sound intrusion and heat loss and is infinitely recyclable.

Soft furnishings: floor covering, windows blinds

Fitted carpets are a health hazard and should be avoided. Use natural fibre rugs which can be taken out and beaten. Soft furnishing are not a good idea if you are prone to breathing disorders (asthma *) as they attract and trap dust. Use cotton or wool - never synthetics which build up static charges and attract dust particles and give off irritating fumes.

Linoleum is still available as a floor covering and is losing its old-fashioned, utility associations. I quite like it and the smell of it. It is made from natural materials and is hard wearing and very easy to clean and germ-free. Being natural it doesn't build up a static charge which can be a problem in a centrally heated house. There are still a few manufacturers around but you might have to search for them.

Don't forget that natural timber, lovingly made by local craftspeople, polished with beeswax, natural turpentine and lavender oil can be a relaxing and luxurious experience.

* If you are prone to asthma, as I am, then you might be interested in my Domestic Toxins page.