The next step in the evolution of the air barrier was the "airtight drywall approach" (Figure 2)--where the interior gypsum board lining became the air barrier (Photo 2).
A "lite" version "airtight drywall approach." It became relatively easy for production home builders to get below 3 ach at 50 Pa and the approach morphed into the EPA Energy Star "thermal bypass checklist" and eventually found its way into the model codes.
Even included: 35 "Breathe Easy" rental homes for asthma victims, engineered for airtight drywall
construction, hardwood floors and improved ventilation.
The airtight drywall
approach is a simple and reliable method for effective air sealing of houses.
However, because the major moisture transport mechanism is thought to be air movement, not diffusion, a construction method known as the Airtight Drywall
Approach (ADA) does not rely on the polyethylene layer.
This lead to the Airtight Drywall
Approach and my Masters and, of course, meeting and worshiping "J.C." like everyone else who met him.