ETFE
LEAF Structures is one of the only companies in South Africa to offer ethylene tetrafluoroethylene (ETFE) design build solutions.
ETFE is a fluorine-based polymer. This membrane is a highly transparent extruded film that can be used in applications as either a single-layer membrane or a multilayer, pneumatically-inflated cushion. The cladding material has good UV stability and anti-adhesive surface properties, is fully recyclable, and is resistant to most common chemicals and environmental pollution.
It has excellent fire performance, with resistance to temperatures up to 200°C and a melting temperature of 270°C. It is a high-performing combustible material and does not add to the flammable mass of a building.
ETFE is also printable, which helps to control the amount of light transmitted through the material and reduce solar gain while retaining a high degree of transparency. By varying the percentage of coverage and density of the ink, the energy transmission can be altered. Digital printing can also be used to create a custom pattern.
ETFE is very lightweight in comparison to glass, making it easier to install. Since each pillow or sheet of ETFE is made up on several strips welded together, less structure is typically used on ETFE applications, resulting in fewer joints and a reduced possibility of leaks.
It can be applied in straight, rounded or free-form skylights, canopies, atriums, and speciality façades.
ETFE photograph courtesy of NMG
Installation
In most cases, ETFE is installed using nets. In ETFE skylights, canopies and roofs, nets are easier and more cost effective to use. This is also an advantage on refurbishment projects, as installation can be done without too much disturbance to parts of the project where other work needs to continue.
Once the steel structure has been installed, nets are attached to the structure and the installation team walks on the nets while wearing safety harnesses to mount the aluminium extrusions and ETFE.
When the installation is complete, the nets are taken off the steel structure.