Terraces, Dry walls and other sustaining walls.
Mother Nature. The geological structures of the natural area have caused the systematic use of stones as the main material for terrace building and soil conservation. In fact, the middle limestone-dolomitic Jurassic layer, known as the Paleozoic Era, was transformed into the "Grand Causses" and the "Gorges du Tarn" by a karst erosion process. Depending on the layers of rock present, all types of stones can be found; over sand and limestone (sedimentary slate) to granite.
It is easy to work with limestone, the right tools and "power".
When restoring, we want to stay true to the traditional drywall constructions of this region. We hope for support from the UNESCO World Natural Heritage Association, which supports the reconstruction of abandoned agricultural zones and their terraces.
Sorting stones by sizes
In accordance with the basic concept of permaculture "to observe before acting", we tried to understand the various terrace designs (referred to as Bancels or further south as Restanques) of our ancestors. Observing a soil, understanding how it breathes, how it is drained by the rain and how it should retain the necessary nutrients determines the type of terrace construction.
We want to restore the walls according to the old knowledge. The most important thing for the terraces is their retaining walls, the type and size of the stones and their laying pattern. Ultimately, the position of keystones plays an important role. These construction techniques are clearly documented on a large number of websites ...
This first try was pretty satisfying, but it was far from perfect.
To fill the hole, I use stones from the immediate vicinity. The placement of the larger stones took more time and strength than expected and the work was very exhausting for me alone.
The vertical keystone on the left had a total weight of 185 kg and the dimensions 45cm x 20cm x 150cm. In order to avoid wrong steps, I hadn't cut or adjusted any of the stones. Our next project will be better prepared; with a larger selection of stones and especially a second pair of helping hands!