The availability of material from the Vesuvian eruptions in the place where the buildings were to be built, made it possible to obtain economic structures and quality. Practically all eruptive products were used on the basis of their physical and chemical characteristics.
Below are the main types using local terminology:
for the foundation plan, excavation was carried out until it reached the so-called “thunder”, a very thickened bank of volcanic ash which, when brought to light, emitted a dull noise if struck
stone in chips, generally compact lava, used for the construction of foundations and perimeter walls.
very vesicular and porous lava generally quite light, used for the realization of arches and vaults
lapillus (pumice), very vesicular and light fragments (floating on water) of small size, used for filling arches and vaults
ASH AND LAPILLI
material also known as “pozzolana”, used to make hydraulic mortar based on lime.