[freebeard]

ETFE transmits UV so it isn't degraded by it. Never needs pressure washing.

www.etferoof.com/

Ethylene Tetrafluoroethylene, ETFE, is a kind of new generation plastic having high chemical resistance and mechanical strength over a very wide temperature range. It is a very molecularly stable material. The strong bonds that exist between the fluoroplymer molecules avoids the degradation of the material due to atmospheric conditions, substances deposited on the material or ultraviolet radiation.

Having 25-30 years of durability, color stability and resistance against becoming brittle, ETFE, with its unparalled alternative to traditional materials, is used successfully for heat insulation and sun control at the façades and roofs.
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Shading with ETFE systems
Whilst base material is very transparent, ETFE foil can be treated in a number of different ways to manipulate its transparency and radiation transmission characteristics by adding more layers, printing, tinting, surface treatments and radiation.

Clever Shading

It is also possible to control the amount of light that is transmitted to the inside by combining 1 translucent and 2 printed ETFE films into a 3 layer design and moving the middle layer up and down. Through this approach, maximum shading or reduced shading can be achieved as and when required. Essentially, this means that it is possible to create a building skin which is reactive to the environment through changes in climate. In such systems the middle layer is programmed to rise and fall (using air pressure) to increase and decrease the percentage of printed area and therefore control solar gain.