##  [Vapor Barrier Failure](/vapor-barrier-failure) 

  ##  [Vapor Barrier Failure](https://engineering.quantumdictionary.io/vapor-barrier-failure-0) 

  

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**Engineering & Applied Technologies Dictionary**

 







 

 

 

 



 

 

 

 

Definition

Loss of continuity, integrity, or adequate permeability control in a building's vapor barrier or retarder layer that permits unwanted moisture‑vapor transport into assemblies under driving vapor pressure and temperature differentials, increasing the likelihood of interstitial condensation and material degradation.