Tags: #buildingmaterials #buildingproducts #buildingscience #facecolumn #fasteners #materialsscience #osb #waterresistance

I’m performing a series of columns with OSB-based WRB panels and various types of over-driven fasteners. Here’s a summary of what we know so far:

  1. Water penetration into the OSB matrix is a function of time, pressure, and individual panels.
  2. The type of fastener appears to have little influence on the rate of water penetration when overdriven by approximately 25%. 
  3. Water migrates between ForceField’s laminated WRB and OSB face with relative ease – nearly instantaneously even at 1” w.c. Pressure fields for all remaining surfaces are no longer ‘static’ due to the rapid release of water between these interfacing planes.
  4. The initial point of release from the OSB matrix is typically the bottom edge of the 1’ x 1’ test panel. A single release point is typically observed at 1” w.c. Multiple release points are observed at increasing pressures.
  5. Water release from the OSB matrix occurs within minutes at 1” w.c. Release is near instantaneous at pressures greater than 4”.
  6. Water penetration to the back side of the panel occurs within minutes at 2” w.c. Instantaneous release has been observed at 4” w.c. 
  7. Void spaces have memory. Once formed and the panel is dried, the void spaces serve to exacerbate subsequent water penetration.