As the most recent flexible sheet material to reach the UK market, single ply has had an immediate impact. Cheap, quick to install and versatile were the primary benefits advertised by the suppliers however we believe these products are suitable only for a certain project profile.
Single Ply materials are in principle mostly as advertised. The price is generally competitive and the installation is quick and easy. However when faced with either tricky roof details or pedestrian maintenance traffic the system suitability is debatable.
Detailing with heat welding or adhesive bonding the seams between sheets can be very difficult and often the integrity of the waterproofing at the detail is not sufficient.
Pedestrian traffic has often caused problems as the systems are prone to puncture. The systems generally 'float' and are only mechanically bonded at set intervals or around the perimeter. Consequently if 'Jack the 18 stone maintenance man' treads on a discarded screw, odds are it will create a very difficult leak to locate.
However on the positive side if you have a project that is an industrial or commercial building with vast expanses of clear roof area and little access, it is unlikely a more cost effective solution will be found.