Why a Permeance Study?
Long before this study was conceived, Stego Industries began in-house testing of vapor retarder/barrier products in the below-slab industry. The impetus for this testing was seeing a wave of significant permeance advancements according to several products' websites and datasheets. The findings from these in-house tests were that many of these products were hundreds of percentage points off (in the wrong direction) from their literature representations.
Armed with this information, Stego tried to warn designers and question a few manufacturers about these deviations. With this message typically falling on deaf ears, Stego decided to anonymously commission a university professor to create a blind study on the permeance of these products.
The next few pages will briefly explain who performed the procurement and testing, how it was anonymous, how it was blind, and why production rolls are a key to this study. After those 4 short pages, you'll get to see the results.