MULTI-LAYER VENTILATED FACADE
A ventilated facade is an articulated system requiring knowledge of the characteristics of the each single functional layer it comprises, analysing aspects and requirements of:
- Covering or external facing;
- Anchoring structure;
- Air gap;
- Insulating layer;
- Perimeter or curtain wall;
- Anchoring elements;
The advantages and performance of some elements must be accurately analysed while for others, albeit of equal importance, a brief descriptive note will be enough.
THE WALL COVERING OR EXTERNAL FACING
It is important to first choose the materials to be used to give the best aesthetic and qualitative results, as it will be the external covering that improves the building appearance.
Indeed, its function is that of characterising the building appearance as well as protecting the walls from atmospheric polluting agents and achieving the performance levels. As a safety measure 5x5 mm fibreglass netting is bonded to the back of each slab to temporarily hold together any broken slab pieces until the tiles can be replaced.
The covering materials of a ventilated wall must meet the following requirements:
- increased mechanical strength;
- increased resistance to thermal shocks;
- reduced water absorption;
- resistance of colours to sunlight;
- resistance to chemicals and air pollution;
- lightweight and ductility;
- limited maintenance requirements.
Porcelain tile or technical ceramic have all these characteristics, making them technically better than quarry materials and classifying them as one of the most suitable materials for ventilated facades.
Technical ceramic tiles are much lighter than quarry tiles and so on unnecessary weight is added to the building, a factor especially important in renovation works, guaranteeing maximum resistance to corrosion due to exposure to atmospheric agents.
The design principle of the ventilated façade lies in the static autonomy of each single facing slab as well as in elimination of fixing mortar.
Not being directly anchored to the building, the covering slab is free to move according to its own expansion coefficient, independently of movements of the structural supports, and to adjust to the settling movements and oscillations of the building thanks to the elasticity of the anchoring.
The joints must be suitably sized to absorb movements, to allow the slabs to shift and expand without interfering with each other.
A joint is simply a gap separating tiles. It has the specific task of allowing the tiles to move freely, in response to thermal expansions and settling movements in the system.
The joints vary between 4 and 8 mm, depending on tile size, distance between building floors and the structure used.