How Does Spray Foam Control Moisture and Condensation?

Most of the damaging moisture within a building envelope is the result of convection currents both through and within the wall cavity.  Warm moist inside air circulates and exchanges with cold dry outside air in a cavity insulated with Fiberglass or Cellulose.  As the moisture in the air condenses, it forms dew within the insulation. This destroys the insulation, decreases it’s effectiveness, and if it is there long enough causes mold and rot.  Both Spray Foam, and other Open Cell spray foams create an air-tight seal and are highly effective at stopping air movement through the wall.  However only Spray Foam with it’s Closed Cell structure can stop the air movement within the wall.  No air movement means no convection, resulting in no condensation, and elimination of moisture problems.