Vapor Pressure

[JackCrump]

Can someone give me a technical definician of "vapor drive" as it relates to moisture migration through building walls that is still reasonavly understandable to a non technical person (insurance claims rep for example). Thank you

 

[boo1]

Moisture flow by vapor diffusion is governed by the second law of thermodynamics (basic physics to some, not so basic to others). Moisture will flow by diffusion because of a concentration gradient as well as a temperature gradient (from "more to less" as well as "from warm to cold&quot. This means that it tends to go from the inside out up north and from the outside in down south. In the middle of the country part of the year it goes from inside out and part of the year it goes from outside in.