Using 2-inch strapping to create a space between the finish wallboard (or plaster) and the air/vapor barrier is now familiar, at least in theory, to many builders. Such a wall leaves space for added insulation, reduces conductive heat transfer through the framing, and — because the electrical wiring can run within the strapping space — makes it easy to install an unbroken vapor barrier. Our building firm, Drerup Armstrong in Ontario, Canada, uses two strapped wall systems: one using 2x2-inch strapping, and another using 2x3-inch strapping. We've found that these systems give much better thermal performance than single-stud framing at relatively little added cost. The Basics The illustration below shows the main elements of the strapped wall system we use. Before we install the poly,
