Polymer-based single-ply membranes are gaining market share from bitumen for waterproofing flat roofs, according to a recent study by Applied Market Information Ltd. (AMI Consulting), Bristol, U.K. As construction activity has strengthened in Europe over the last few years and the market continues to shift toward lighter weight and faster construction techniques, the growth in demand for single ply has risen significantly. Technical innovations in polymeric single ply have resulted in improved durability, enhanced aesthetics, easier installation and improved bitumen compatibility. Two growth areas are repair of old bitumen roofs and on single dwelling residential buildings.