Sandtoft VPM Classic & Sandtoft VPM Super can be used with all concrete and clay roof tiles and slates and are suitable for both warm and cold roof designs on any roof shape and building type. Both membranes perform all the usual functions of a good quality roof underlay; i.e. they act as a secondary line of defence against wind driven rain and snow, they reduce the wind loading on the roof tiles and slates and act as a temporary roof covering during building construction. These membranes also provide many benefits over the traditional bitumen-based underlays; in particular they help avoid condensation in the roof space. Sandtoft VPM Classic & Sandtoft Super provide additional protection to the internal roof substructure during extreme weather conditions where wind-driven rain or snow may drive through the tiles or slates by safely draining it away to the gutter or other rainwater system. Often the roof underlay must act as a temporary waterproof covering until the tiles or slates are installed. Sandtoft VPM Classic & Sandtoft VPM Super will provide temporary protection against rain for up to a month prior to the installation of the tiles or slates. Specifications Length: 50mWidth: 1000mmZonal Classification (with Max Batten gauge 345mm):Untaped: Zone 1Taped: Zone 1 to 5Zonal Classification (with Max Batten gauge 255mm):Untaped: Zone 1 to 5