’s Air and Vapour Barriers category features Lexcor’s premier Air and Vapour Barrier, Lexshield. Lexshield is a self-adhered Air and Vapour Barrier Membrane for use in walls and roofs. Available in 4 inch, 6 inch, 9 inch, 12 inch, 18 inch and 36 inch wide rolls, Lexshield possesses excellent air and vapour barrier properties, is flexible, is tear and puncture resistant, can be applied in temperatures as low as -20°C (-4°F), self-seals around screw and nail penetrations; and in most cases, does not require a primer prior to application.