An important part of the solution to avoid structural damage is to install an air barrier in your wall system. Air barriers are designed to prevent the flow of air and the moisture attached to it from entering the building envelope. Approximately, 100 times more water vapor is carried into walls by air leakage than is carried by vapor diffusion, making an air barrier more critical than its counterpart, a vapor barrier.
“Leaking exterior doors are a common problem affecting building owners and tenants, causing property damage, and requiring expensive repairs. Designers and builders are aware of the issue.