Closed-Cell Spray Foam
Closed-cell spray foam insulation is one of the most efficient insulating materials commercially available, with aged R-Values above 6.5 per inch. The description “closed-cell” comes from the cell structure of the finished insulation material. One cubic inch of polyurethane foam insulation contains millions of tiny plastic closed cells.
The blowing agent is captured within the cells which contributes to highly efficient insulating properties. In addition, closed-cell foam provides an inherent air barrier with low moisture vapor permeability, and excellent resistance to water. The density for closed-cell spray foam is approximately two pounds per cubic foot. The medium density foam provides sheer and racking strength to wall assemblies in building applications. Due to the structure of closed cell spray foam it is the primary use in agricultural applications of spray foam insulation. Small imperfections in the building envelope (holes, cracks, gaps) not properly sealed will eventually lead to poor building performance or worse, moisture accumulation, allergen/pathogen growth, and very possibly structural failure. The solid nature and sealing capability of closed-cell spray foam, inhibits moisture-driven elements. Two inches of closed-cell spray polyurethane foam insulation will minimize air infiltration, exfiltration, convection, conduction and control solar driven moisture in the building envelope.
In residential applications it is common to apply 2″ of closed cell spray foam insulation to the walls and 3″of closed cell spray foam insulation to the underside of the roof deck and gable ends of the attic system. There are multiple application factors that go into the decision of how much and what type of insulation goes into a residential home and whether closed cell spray foam insulation or open cell spray foam insulation, both provide an upgrade over conventional fiberglass or cellulose.