Slate is a natural sedimentary rock, which is obtained almost by hand and has different uses, including serving as a roof covering.
It is a material that was widely used in Spain and France (in Spain it is very abundant and that is why it is more easily obtained), but currently it is not as widespread or it is not “fashionable”.
However, those interested in sustainable construction and architecture should know that, at least in areas where it is locally available, slate is a sustainable, malleable, natural thermally insulating option worth considering.
Why is blackboard sustainable?
To assess whether a material is sustainable, we must compare it with those that we would use instead. For the manufacture of tiles, for example, ceramics are used and in this manufacturing process much more carbon dioxide (pollutant) is produced and more water is consumed than in obtaining slate.
An asbestos-cement roof, for example, emits 4.5 times more CO2 in its manufacture than the process that would involve covering the same roof with natural slate. As for ceramic tiles, they consume three times more water in their manufacture than slate tiles.
The energy needed to make ceramic tiles, fiber cement roofs or different types of sheet metal is between 1.5 and 3 times more than that required by slate.
Slate roofs can be kept intact for hundreds of years with little maintenance, and also, as it is a non-conductive material, it allows savings in heating and cooling systems, unlike common roofing materials but lousy in that aspect such as the plates.
Also, aesthetically these ceilings can be very beautiful!