The raw earth, an historic feature of the Valdelsa construction industry

The raw earth, an historic feature of the Valdelsa construction industry

The raw earth, this unknown

Fall 2002

I went to Lucardo because I had been notified of some buildings with earthen walls. Armed with a camera, I was wandering among the houses when a lady, who was looking at me a little curiously and a little frightened by my suspicious strolls around the houses, asked me what I was looking for. – “Good evening lady, I have been informed of the presence of earth walls …” – she replied resolute and reassuring – “No! Don’t worry, nothing has collapsed here. The walls are all standing!”. I smiled at her and left. There were no walls that had collapsed to the ground; he must have thought that I was a zealous surveyor of the Civil Engineers.

The walls built with “raw earth” are not well known and always arouse certain amazement as if they were a rarity. On the contrary, in Valdelsa, rich in clay and sandstone, they are or rather were, the norm. The loss of technical knowledge in working the land for construction has caused problems related to the recognition of the construction technique itself. We often refer to “rotten” walls, to be removed. Indeed, at times they have been mistaken for internal cladding with no structural function and then removed, causing damage to the building.

The findings of the Achu Archaeological Group

The raw earth house was a characteristic element of our landscape (and it still would be!), of a way of living. In the “land of Semifonte”, between Barberino VE and Certaldo the ProLoco Archaeological Group Achu in the past years has promoted a dissertation thanks to which many earth buildings have been catalogued and identified. The techniques vary from raw brick to Pisé. Perhaps even in blocks of earth stacked and compacted side by side.

The most common technique involved the use of wooden formwork, as is used today to contain and delimit the concrete casting, inside which layers of earth were compacted. A mixture of sandstone, clay, probably a small amount of lime, straw, dung, gravel and ceramic fragments was used. Precisely the latter if we recognize the dating provides us with important chronological data on the construction of the building. But often in private historical archives, you will find the information necessary to establish the date of construction. Sometimes the earth wall is far older than we can imagine.

A look at the presence of the raw earth

In Italy, we have a study centre on clay construction that offers interesting solutions also in terms of modern green building. We feel the duty to spread this news not only for the protection of our heritage but also to stimulate investments aimed at a more sustainable building development.

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