4a How to install DuPont™ AirGuard® vapour control membrane on rafters: Learn more about the simple, effective way to connect a vapour control membrane to a wall using DuPont™ Tyvek® and AirGuard® energy solutions: Tyvek® Double-sided Tape, Tyvek® Acrylic Tape and Tyvek® Butyl Tape for an airtight seal.