Polyisocyanurate Insulation and the Vapor Retarder Paradox

摘要

The 'warm wall' design is based on a temperature-controlled design approach and, as such, removes the headache of attempting to control moisture purely by a traditional 'water vapor permeance' design approach. As energy codes continue to advance, the traditional vapor retarder design has become more and more challenging to reliably implement. However, the use of continuous insulation (ci) for a warm wall design creates an opportunity to leverage newer energy code insulation requirements in a way that also improves the building's moisture performance.