The preliminary steps to carry out in designing a ventilated facade are:
- 1. examination of the designs and/or architectural concept for the building covering;
- 2. feasibility study;
- 3. identification of the materials that make up the wall facing to be covered;
- 4. identifi cation of a structural plan and the respective general calculations;
- 5. completion of the detailed fi nal drawings and plans.
One of the most important design decisions affecting the final result is whether to use exposed or concealed anchoring devices for the slabs.
This choice basically involves two considerations:
- the aesthetics of the facade at a close distance;
- the economic aspect, which must also be evaluated according to the modularity of the chosen slabs.
When preparing a building for the installation of a ventilated facade, the architect must take into consideration an approximate weight of 28-30 kg per square metre for a cladding system using porcelain stoneware slabs, and a “ventilated package” thickness of between 110 and 150 mm.
In construction terms, the main difference between the two groups, apart from the method of slab-to-structure anchoring, is that concealed systems make use of a horizontal frame of crosspieces, which are placed between the uprights and the anchoring elements.
Brackets, uprights, and crosspieces of different shapes and sizes can be used in each group according to the modularity of the slabs, whose size is bigger and bigger, and the specific wind loads. In a ventilated facade, the covering material is secured and supported by a load-bearing steel structure anchored to the building walls. This structure is composed of the following elements:
- Brackets anchored to the building walls, which may be more or less frequently placed depending on the load-bearing needs and wind loads.
- Vertical uprights anchored to the brackets. They are fixed at a specific centre-to-centre distance according to the size of the slabs used for the facing.
- The alignment of these profiles is the most critical part of the system for achieving a flat, straight wall.
- Horizontal framework, intersected with the vertical uprights, present only in the case of concealed anchoring systems. Fibreglass netting bonded to the back of the slab temporarily holds together any broken slab pieces until the slab can be replaced, which is a simple operation.