Environmental impact of slate transportation from near and far

Tuesday, 16 February 2010

Slate is a beautiful, naturally occurring, organic material and is one of the most sustainable forms of roofing. Independent research has concluded that when compared to concrete or clay tiles, or to copper or lead, slate’s minimal processing gives it the lowest embodied energy of all roofing materials. The same research also states that its long life expectancy, low maintenance and recyclability give slate further credibility in terms of environmental impact.

Due to the paucity of domestic slate supplies, specifiers are increasingly looking abroad. Natural roofing slates are imported into Britain from around the world, principally from Spain, but also from Brazil and China. Slates are normally transported in containers by a 40 tonne articulated truck, from the quarry to a designated port and then by ship to a port in Britain. Carbon emissions generated by road and sea transport will affect the slate’s overall environmental impact.

Independent research has been carried out to determine the carbon dioxide emitted during the transportation of slate from quarry to stockist.

Galicia and the North Western region of Spain is the UK's closest meaningful slate producing neighbour. The research showed that emissions for transporting slates from North Western Spain to Britain could be as little as 800kg. Extrapolation of the data for transporting from quarries 200km north of Belo Horizonte to Rio de Janeiro and then on to Southampton resulted in total emissions of 4401kg. It was similarly calculated that the carbon dioxide emitted in transportation from China to Britain was around 8000kg.

There is always an environmental impact in transporting any commodity. Given that, it is clearly preferable to look for a source as close to home as possible, making Spanish slate the ideal import choice for the UK market in terms of environmental impact.