REMOVAL NOTICE: Field research study for investigating wetting and drying characteristics in wood-framing walls subjected to cold climate

Abstract

A field research study was conducted to investigate the wetting and drying characteristics in three 2 × 6 wood-framing wall specimens when they were subjected to different heat, air, and vapor flow transmission. The stud cavity of the wall specimens were filled with glass-fiber insulation having a nominal thermal resistance of R-20. The three wall specimens consisted of an exterior oriented strand board sheathing of 11-mm thick, spun-bonded olefin membrane, and vinyl siding. To investigate the effect of air/vapor barrier on the moisture performance, the first and second wall specimens, referred in this paper as “W1” and “W2,” included a 6-mil polyethylene sheet that was installed on the interior side of the stud cavity, behind a painted drywall. However, in the third wall specimen, referred as “W3,” the interior side of the stud cavity was closed by painted drywall without air/vapor barrier. To investigate the effect of the exterior insulation on the moisture performance of wood-framing walls with an air/vapor barrier, an insulation board made of extruded polystyrene (XPS) (50 mm thick and having a nominal thermal resistance of R-10) was installed in the wall specimen W2 on the exterior side of the spun-bonded olefin membrane. With and without air/vapor barrier, and with and without exterior insulation, this research study accounted for different parameters that may affect the wetting and drying characteristics in the wall specimens. These parameters included the pressure differential across the wall specimens, indoor humidity, outdoor cold climates, and air leakage as a result of creating deficiencies that provided a path for air leakage in the wall specimens. A test protocol was developed in this study that permitted investigating the effects of these parameters on the hygrothermal performance of wood-framing wall systems.