As a field technician, I spend a large percentage of my time working with contractors. This involves attending preconstruction meetings, site visits and providing installation training on mock-ups. From my experience, I would like to share with you some of the issues commonly encountered.
The first issue that should be confirmed is if the project has been specified as either a weather resistant barrier or an air barrier. In order to be classified as an air barrier, the membrane must be continuous, without breaks on all six sides of the building. If the details do not represent a continuous seal, then you have yourself a WRB. You would be surprised on the lack of clarity on this matter.