Ventilated facades in terracotta: undisputed advantages in wall cladding
Within the contemporary construction sector, the non-load-bearing curtain wall can be considered as an innovative technological construction system. Such a system consists of an insulating layer that is applied directly to the supporting structure of the facade and of a cladding layer that is fixed to the building. This creates an air space between the insulator and the cladding that activates effective natural ventilation through the upward draft of warm air, with significant benefits for the entire system.
There has been experimentation for centuries with insulating the curtain wall. There are many traditional structures with air spaces between an outer cladding of wooden slats or slate slabs and a fastening system consisting of wooden keyways attached directly to the load-bearing structure of the building with screws or nails. Considering the areas where these types of cladding are widespread (Liguria, Alpine regions, Northern European regions), it is clear that they were originally invented to seal the exterior walls against driving rain, characteristic of windy areas.
A huge range of materials is being used in exterior cladding systems: marble and granite, wood, ceramics, terracotta, reconstituted or fiber reinforced materials, laminates and plastic materials in general, metals (aluminium, steel, copper, alloys) etc.
In cavity walls, the elements of the protective layer that are in contact with the exterior are mechanically anchored to the underlying structure to provide an air space that can create natural ventilation. In recent construction activities, the main architectural achievements have often been achieved through the use of traditional materials such as stone, wood and more recently terracotta.
Technological research in terracotta production has led to the development of innovative terracotta facade products such as pre-assembled panels mounted on a more economical wall structure. This is based on an economic rationale: reducing the thickness of cotto elements and expanding the other dimensions that determine their visible size on the cladding surface. A reduction in thickness unquestionably lowers costs associated with excess material and weight, which in turn leads to more economical transportation, machine shifting and labor. Most importantly, in the case of cladding anchored to a cavity wall, reduced thickness also means smaller mechanical fastening systems.
Contemporary terracotta facade systems have undisputed advantages: – (improved) waterproofing – reduced risk of cracks and loosening, typical of cladding applied directly to the wall structure; – easy application and maintenance; – better protection of the wall structure against weather influences; – more comfort in both summer and winter; – remarkable energy savings.