The excellent mechanical and self-cleaning properties make ETFE the ideal material for different applications in architecture.
ETFE roofing has gained popularity in construction since its first application at the Burges Zoo in 1982. Today, it is successfully utilized in several buildings.
The most commonly used technology for ETFE roofing consists of two or more layers inflated with dry air, creating ETFE cushions. With an accurate design of the membrane cutting pattern, even the most demanding load conditions can be effectively managed.
Wind loads are typically managed through the overpressure of the cushions, which can be controlled in an adaptive way to maintain internal pressure higher than external pressure caused by the wind, preventing fluttering problems.
If there are exceptional snowfalls with loads exceeding the internal pressure of the cushions, the cushions may partially or fully deflate. In this case, the ETFE layers overlap to distribute the load evenly between different layers, ensuring roof coverage and safety even in extreme conditions.
Additionally, if snow loads are extraordinarily high or cushions are oversized, structural support cables may be added to reduce excessive deformation of the ETFE foils when loaded with snow.
Single-layer systems are not commonly used as roofing systems due to the risk of excessive elongation of the ETFE beyond the elastic range. These systems are generally utilized in areas with limited snow loads and are usually reinforced with support cables.
Thanks to the absence of snow loads, ETFE facade systems are characterized by considerable geometrical freedom with fewer technical limits due to the risk of water stagnation and the accumulation of snow and ice.
In addition to two or more layer cushion systems, modular panel systems or double-curved single-layer systems can be successfully used.
As for the roofs, also in ETFE façades, it is possible to integrate ropes or nets of support ropes that guarantee the construction system even in tropical areas with winds over 36 m / s.
One of the key advantages of using ETFE for facade systems is the possibility to obtain complex three-dimensional shapes at a low cost, especially if compared to glass facade systems.
Greenhouses and winter gardens in ETFE
Greenhouses and winter gardens are one of the most natural applications of ETFE systems thanks to the high transparency of the material, even in the spectra of solar radiation generally shielded by glass panels.
In addition to optimizing thermal gains in the winter season, the high transparency of ETFE increases fruit and vegetable cultivation yield by reducing chemical treatments thanks to the fungicidal action of ultraviolet radiation from sunlight.
In addition to the greater transparency of the covering film, there are also the advantages of a less bulky support structure that reduces the shade on the underlying crops.
The Eden Project in Cornwall is undoubtedly the best-known example of an ETFE greenhouse.
Still, the system can also be used successfully for less expensive applications in agriculture, allowing the rapid and efficient replacement of glass panels or traditional plastic films.
Art installations with ETFE
Digital printing created new opportunities and different possibilities for the customization of ETFE films which have become an alternative to PVC or PU films for applications that require better mechanical strength and aging when exposed to sun rays.
Recent applications of art installations include the Coca-Cola Beatbox pavilion for the London 2012 Olympics (Asif Khan and Pernilla Ohrstedt), the 2015 Serpentine Gallery pavilion (SalgasCano), and the artistic installation Invisible Borders per il Fuorisalone di Milano 2016.
Retrofitting and improvement of existing buildings
Thanks to the lightness and flexibility of ETFE film systems, it is possible to retrofit existing buildings by improving their aesthetics and thermal performance without compromising their structural behavior.
The extremely low self-weight per surface unit (2-3.5kg/m2) does not increase the structural stresses in case of an earthquake and, at the same time,e reducing the risk of debris from detaching from the facade or the roof, injuring passers-by.
Temporary structures in ETFE
Due to the material’s flexibility, temporary structures such as pop-up shops, fairs, or traveling events are generally made of PVC fabrics and films.
However, the recent experience of the itinerant pavilion for the Yamaha MotoGP hospitality area has highlighted the feasibility of modular ETFE facades for nomadic structures and temporary architecture traditionally made with materials other than ETFE.