Membranes made of PTFE-coated fibreglass fabric are of even higher quality. In this case, the surface coating is made of Teflon polymer, which has a virtually self-cleaning effect. In addition, this material is non-flammable (A2 / DIN 4102), which is a design criterion for some projects. The average service life of these structures is 30 to 40 years; as with the other materials, UV resistance is also very good. Membrane structures made of PTFE-coated fibreglass fabric have a translucency of 8-25%, which creates a particularly bright atmosphere under the structures. Here, too, use is primarily relevant for permanent structures. The material is beige at the beginning and then bleaches completely within a few months.