Analysis of the surfaces of the walls and the building techniques and materials, showing up the restoration stages and the repair work

The main characteristic of the bastide of Vianne is undeniably its simplicity. The simpleness of the original defensive system: a tower and gate at the ends of each of the two axes, round towers at the corners (with one more tower on the non-linear rampart). Simplicity, too, in the materials used for its construction (quarry stone). This quarry stone is limestone taken from different pits and whose sides sometimes include conchoidal cavities.
All these facades have the same structure : a base of 40 to 45 cm, which is the emerging part of the foundations. An elevation of 18 layers of cut stones of blocks varying from 25 to 45 cm in length and 20 to 28 cm in height.
The original surface has been reproduced within the framework of the general restoration, respecting the quality of the stone and the size of the blocks. The heights established at the beginning of the century depend on the facades. A height of 4 to 5 metres has been foreseen for restoration of the defensive walls. The extra layers required can be recognized by the whiter colour and smoother surface of the stone, which shows the intervention of technicians.
The rampart walk appears on the internal surface of the thirteenth layer, that is to say at about 3.5 metres, with a parapet whose machicolations have been restored on each side of the gates, at the ends of the main axis. The quarry stones are jointed by using a thin coat of lime mortar, which levels the stone.