Most modern building enclosure assemblies are constructed in a series of layers that perform one or more specific functions. Some of these layers are critical for the performance and durability of the assemblies and functional names have been assigned to them such as air barrier, vapor barrier/retarder or moisture barrier.
There has been a move recently to discuss them in generic terms of “control layers” including air control layer, thermal control layer, vapor control layer, moisture control layer and rain shedding surface.
Each of the control layers has its own functional requirements with respect to continuity, location relative to other control layers and attachment to the structure. In other walls, the control layers can be provided by different material layers. In adjacent assemblies the material and the location of the control layers can be quite different. A high percentage of performance failures in enclosure assemblies can be attributed to insufficient continuity or incorrect connections of these control layers at the junction of different assemblies. This presentation will describe in detail a systematic approach to identifying potential performance problems at the design review stage.