Sandtoft VPM Classic and Sandtoft VPM Super vapour permeable membranes can be used with all concrete and clay roof tiles and are suitable for both warm and cold roof designs on any roof shape and building.
Underlay Features
Learn more about Sandtoft underlay
Installation
When laying Classic or Super over counterbattens or rafters, allow the underlay to drape approximately 10mm. This allows any moisture on the upper surface of the underlay to drain away safely under the tile/ slate battens, preventing ponding behind or wetting of the battens. Where a horizontal lap does not coincide with a tile/slate batten either fix an extra batten over the underlay lap or increase the lap to coincide with the next batten.
Secondary Line of Defence
Sandtoft VPM Classic and 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.
Temporary Roof Covering
Often the roof underlay must act as a temporary waterproof covering until the tiles or slates are installed. Sandtoft VPM Classic and Sandtoft VPM Super will provide temporary protection against rain for up to a month prior to the installation of the tiles or slates.
Accessories
Underlay support tray 1500mm.
