Why is ETFE foil the best choice for transparent roofs?
In case of transparent roofs, ETFE material offers significant advantages over glass, PVC or PTFE. These include extremely low weight compared to glass, exceptional light transmission, especially in the UV spectrum, a self-cleaning effect, elasticity, long service life and sustainability.
ETFE foil is a hundred times lighter than glass. The particularly low weight of ETFE enables roof designs that would be impossible with other materials. As a result, it also reduces transport costs and enables more efficient substructures.
ETFE roofs are characterized by their long service life, low maintenance and UV transparency
ETFE roofs or canopies allow the transmission of almost the entire UV spectrum (95 percent). This makes them ideal for buildings containing plants that need UV light for photosynthesis.
If full exposure to the sun is not required, ETFE plastic foil can include a number of frit patterns within the material. This method can be used to adjust shading as required. Due to the self-cleaning effect, ETFE structures are low maintenance and highly durable. And in terms of color: The opacity of ETFE foils can be varied from 5 percent to 90 percent, depending on your requirements.
Roofing with ETFE offers even more benefits. ETFE foil offers excellent elasticity and its breaking point is higher than that of any comparable material. If you chose NOWOFLON ET as your ETFE foil the tensile strength is rated at 23 N/mm² at the limit of the material's plasticity at the elastic limit and > 55 N/mm² at break. Few materials can match such strength for the amount of elasticity.
ETFE roofs offer excellent sustainability
Sustainability is one of the main arguments for ETFE roofs. From the extrusion of the ETFE foil through to transport and installation, the light weight of the material reduces the CO2 footprint significantly. ETFE foil can be useful for the building's thermal design.
In case of a greenhouse ETFE roofs can trap warm air inside the building to improve its thermal properties. This in turn reduces heating costs. If you want to keep warm air out of your building, ETFE foils can be produced with an appropriate opacity to achieve that too. And when no longer needed, the ETFE pillows can be fully recycled after their long service life of at least 25-30 years.
Do you want more detailed information about ETFE roofing? Contact us now.
What do experts have to say about ETFE foil?
Stefan Behnisch - Architect
"We were looking for a material to form the outer film for a double facade. Single-layer ETFE was perfect. It is lightweight, innovative and visually attractive thanks to the high-tech look of the back span. The use of ETFE was also ideal from a fireproofing standpoint. ETFE is very transparent and almost impossible to tear when used in single-layer applications. The film is structurally stable and extremely durable. It’s easy to keep clean thanks to the “lotus effect” and offers an excellent cost-benefit ratio."
Florian Weininger - Engineer
"The quality of our planning and structural calculations depends on the material properties we take into consideration. The high quality of NOWOFLON products and the professional consultation with their staff helps us ensure that our clients really get what we promise in our planning."
Direct comparison: ETFE roof vs. glass roof
ETFE foil offers greater thermal performance. This is made possible by the multi-layered ETFE foil system. Although a single-layered ETFE roof is perfectly possible from a technical standpoint, the ability to trap heat increases as more layers are added. Therefore, double-, triple- or more layered roofs are preferable when thermal insulation is a priority in the building's design
ETFE roofs are superior in terms of safety
ETFE roofs are also superior in terms of safety compared to glass roofs. In the event of an earthquake or collision, a glazed roof will often shatter, which can be extremely dangerous for anyone who happens to be beneath it. Conversely, an ETFE roof will not send shards falling down.
Last but not least, an ETFE roof requires significantly less maintenance. Thanks to its non-adhesive surface properties, an ETFE roof can clean itself of the usual grime and dust with which it will come into contact. Even larger debris will not stick to the roof and will be washed down by rainfall.
The ETFE roof of Saint Petersburg stadium
For the 2018 World Cup in Russia, we participated in the construction of a state-of-the-art moving ETFE roof that uses a special transparent material: our ETFE foil NOWOFLON ET 6235 Z. This material covers the roof of the stadium and ensures the perfect light and temperature conditions for soccer players, regardless of whether the roof is open or closed.
NOWOFLON ET 6235 Z is a transparent fluoropolymer film, which provides an outstanding combination of properties and in addition scope for color design that makes it an ideal material for use in membrane construction.
The ETFE foil NOWOFOL ET 6235 Z perfectly met the requirements
Located on the Baltic Sea, Saint Petersburg has a harsh climate that places high demands on the material. This was taken into account when planning the roof and choosing the ETFE material. NOWOFLON ET 6235 Z boasts a thermal service range of -200 to +150°C and a melting point of 265°C, making it the perfect solution for the requirements. The EFTE foil cover on the stadium’s roof consists of 96 cushions, with 36 located on the fixed roof section and 60 on the moving section. We manufactured over half a million square feet of ETFE foil.
Would you like to see more? You can find more examples here.
Become an example of a successful ETFE project yourself and let’s talk about what is possible. Contact us now!