Dupoint Tyvek Vapour Permeable membranes are suitable for use as secondary water shedding layers in roof and wall construction. They are highly water resistant polyethylene materials with hydrostatic pressure tests that exceed 2m (BS EN 20811). The material's resistance to water vapour   is low, thus allowing moisture laden air to permeate through the membrane to outside air. This function eliminates the need to ventilate between the products and the insulation. Certification from the BBA demonstrates compliance for the use of TYVEK membranes in non ventilated tiled and slated pitched roof construction

GENERAL COMMENTS

Tyvek roofing membranes are laid in the traditional way, i.e. Parallel to the eaves. All horizontal laps must be in accordance with the requirements of BS5534 Code of practice for slating and tiling. Counter-battens must be used where Tyvek Supro or Solid is laid directly onto insulation or timber boarding (not applicable in traditional Scottish boarded roofs). Counter-battens are not required when Tyvek Supro is installed in a draped condition over rafters. Both Tyvek Supro and Solid may be laid eaves to eaves (up and over) if required. Tyvek membranes, when properly secured, may be left exposed for a period not exceeding 6 months.