The two layer Duo system consists of a 4.3mm capsheet torched to a 2.5mm basesheet, to form a 6.8mm thick roofingsystem designed by Belgium waterproofing company De Boer, and is used all over the world. Duo roofing membraneprovides a hard, stable, UV-resistant, but flexible modified bitumen product, finished with pressed coloured slates for use in sealing old and new, flat and near-flat roofs. The system has been assessed within the New Zealand Building Code and can be used on substrates such as plywood and concrete to form a standard cold roof system.
The Duotherm warm roof system sees the Duo system installed over a rigid PIR insulation board to provide thermalinsulation with a guaranteed R-value of over R3.5.