Prior to the mid-20th century, building walls relied on their thickness and density to resist water penetration. Moisture would mainly deflect from the wall face or be absorbed and later evaporate from the mass wall.
Every professional builder knows about the damaging effects of unwanted moisture, as well as how challenging it is to control water intrusion in certain climates. However, What is not always understood is the role airflow plays in moisture control and how important air barriers are in managing it.
Insulating walls with low-pressure sprayed polyurethane foam (SPF) is a common practice among builders and architects for various reasons—such as increased energy efficiency, structural support, and overall comfort.