ESWA - We about us
ESWA - Roofing
ESWA - Civil Enginieering
ESWA - Plastics and Environment



Materials

Thermoplastic roofing and waterproofing membranes - Membranes for all seasons. When it comes to covering the large-area roofs of industrial and commercial buildings, thermoplastic roofing membranes have the edge. And in renovation projects they also have considerable advantages.

Sales of the companies belonging to ESWA (European Single Ply Waterproofing Association), representing 85% of the market for thermoplastic roofing and waterproofing membranes, have risen steadily in the last few years. PVC accounts for about 2/3 of the roofing membranes laid and other plastics for the remaining 1/3.

Made to measure

The boom in the development of thermoplastic roofing membranes started in the Fifties. Not only PVC, but also PIB, ECB, EVA, PE-C and, in the Eighties, FPO were developed to market maturity. Thermoplastic roofing and waterproofing membranes have decades of success behind them, and their properties and applications are listed in detail in the flat roof guidelines. As they are usually laid in a single ply, they are a good deal faster to lay than other waterproofing systems. The different types of laying - mechanical fastening, loose laying under ballast, and full bonding - offer the right solution for any building being waterproofed. Thermoplastic roofing membranes should not be thinner than 1.2 mm, otherwise the waterproofing capability may be put at risk. The products of ESWA members meet the highest standards, while those of non-ESWA members may well fall short of the mark.

As a "custom made" material, plastics can be produced to customer specification and are thus suitable for a wide range of applications. The raw materials, with their reproducible and precisely defined properties, come from highly sophisticated chemical plants where quality fluctuations are out of the question. Quality assurance on the production sites extends from the control of incoming goods through to the inspection of the finished product. Certification to ISO EN 9001 ensures comprehensive documentation of the production process.

The materials

Roofing and waterproofing membranes made of ethylene copolymer bitumen (ECB) are bitumen-compatible, free of plasticizers and halogens, and have been on the market since 1968. BASF combined the product properties of bitumen with those of polyethylene copolymer to create a new material in which the share of plastic ranges from 50 to 75%.

Ethylene vinyl acetate copolymer/terpolymer membranes (EVA) are membranes made of a thermoplastic copolymer. These bitumen-compatible roofing and waterproofing membranes are weldable. The first patents for making polyethylene flexible with the aid of vinyl acetate go back to 1938. The reverse approach has since proved better, with vinyl acetate being modified with PVC since 1971.

Roofing membranes made of flexible polyolefins (FPO) are distinguished by their flexibility combined with mechanical strength. UV- and chemical-resistant, they have a long service life. FPO membranes do not contain any physically incorporated plasticizers, can be formulated halogen-free, and are bitumen- and PS-compatible. FPO membranes have been used in civil engineering since the Seventies and as a waterproofing system on roofs since the beginning of the Eighties.

Halogen- and plasticizer-free PIB roofing membranes have been in use as waterproofing for roofs since 1953. As a waterproofing system for buildings, they have been standardized and approved in Germany since 1961. In addition to serving as a waterproofing system for roofs and buildings, it can also be used as acid protection.

PVC membranes have been in use since the Fifties. Monomer-plasticized, calendered PVC membranes were joined in the Sixties by polymeric, extruded PVC membranes. This was prompted by the demand for a flexible, bitumen-compatible waterproofing membrane resistant to many aggressive media such as mineral oil and fatty acids. The bitumen-compatibility demanded specifically in renovation projects and neutrality towards insulating materials was now available even without a separating layer. Another benefit of these membranes is that they are sufficiently permeable for damp roof layers to dry out reliably after renovation.

Permanently tight

Studies show that the EN requirements of new products can be fulfilled by modern roofing membranes even after decades of use and that their mechanical values barely differ from those newly laid. This means that practical experience has confirmed the weathering tests conducted by manufacturers. Artificial long-time weathering (xenon test) shows, for instance, that thermoplastic roofing membranes are extremely resistant to UV radiation and the values achieved are (up to eight times) higher than the demanded DIN EN values.

The ESWA companies sell FLL-tested thermoplastic roofing membranes which, thanks to their smooth seams and their mechanical strength, are resistant to couch grass roots and rhizomes without the addition of rooting inhibitors.

Thermoplastic roofing membranes: Membranes for all seasons

Applications/ laying method
Mechanical fastening
Loose laying with ballast
Bonded laying
Functional separation by loose-laying the individual layers
X
X
 
Entire system of layers secured against lift-off due to wind loads
X
X
 
Surface easy to check
X
 
X
Compensation for movement by flexible roofing system
X
X
 
Low own weight
X
 
X
Largely independent of roof pitch
X
 
X
Largely weather-independent laying
X
X
 
Simple removal and recycling of pure-grade materials
X
X
 
Low fire load
X
X
 
Durable, cost-effective
X
X
X
In successful use for decades
X
X
X


System advantages of various laying methods according to application