Applied Market Information Limited has announced the international conference on Waterproof Membranes to be held 26-28 November 2007 at Cologne, Germany.
Waterproofing membranes are commonly used in flat roof construction and have other applications, for example in geomembranes. In the early years geomembranes were used mainly as canal and pond liners, now they also find wide use as liners for waste including hazardous chemical materials, as well as covers. The most popular geomembrane materials include reinforced PP, PVC, HDPE, LLDPE, chlorosulfonated polyethylene and alloys. Geotextiles are often used as reinforcement.
A variety of polymers is employed in the roofing industry including polymer modified bitumen, PVC, EVA, thermoplastic elastomers, butyl rubber, chlorosulfonated polyethylene, chlorinated polyethylene and EPDM.
'Flat' commercial roofing systems were made predominantly of multi-ply bitumen systems until the 1990s. The polymers used in bitumen include atactic polypropylene, styrene-butadiene-styrene (SBS) and synthetic rubber. SBS gives the bitumen rubber-like characteristics and improved resistance to ageing and weathering. Atactic polypropylene enhances the UV resistance and low temperature flexibility of bitumen while improving its flow resistance at high temperatures.
EPDM, usually with carbon black as an anti-UV additive, is used in single-ply membranes with some kind of ballast for wind resistance and often an insulating foam layer. PVC is also used in single-ply membranes and comes in other colours. It holds a large share of the market but suffers from plasticiser loss over time, which can cause embrittlement. TPOs have been used since the 1980s and are reinforced. Other single ply materials include chlorinated polyethylene, chlorosulfonated polyethylene and PVDC.
The materials used in construction must meet strenuous performance requirements covering factors such as weathering (resistance to UV, cold, heat, wind lift, rain and environmental stress cracking) and fire resistance. They must withstand a variety of factors such as cigarette burns and pedestrian traffic.
There are new developments in construction such as the cool roof concept. Studies have shown that urban areas can be up to 6-8o hotter due to the lack of vegetation and the amount of darker materials which absorb heat - this is known as the 'urban heat island' effect. In hot areas solar reflectance and heat radiation are important to cut temperatures in buildings and reduce the amount of air conditioning needed. Reflecting heat can also reduce the ageing rate of the roofing materials. Pigments can be used to reflect heat from the surface and just for decorative effects - colour change with time then becomes more important in the application.
Green roofs are becoming more common and Germany has been at the forefront of these developments - plants are grown on the roof surface. The plants usually mesh with the underlying roof fabric and help to prevent wind lift. This protects the underlying structures but adds another challenge for the roof planners - membranes must show root growth resistance. Green roofs also provide extra insulation and can be an effective form of cool roofing. Polymer modified bitumen and PVC membranes have been used extensively and some green roofs have been in place for over 35 years.
Waterproof Membranes 2007 is a networking opportunity for suppliers, membrane manufacturers, and the construction industry to discuss the latest developments in markets, legislation, technology and materials. The deadline for sending an offer of a paper to is 25th May 2007.
{{comment.DateTimeStampDisplay}}
{{comment.Comments}}