Air/Vapor Barriers

Controlling heat flow, airflow, moisture flow, as well as solar and other radiation will control the interactions among the physical elements of the building, its occupants and the environment.

Of these four, airflow “merits major consideration mainly because of its influence on heat and moisture flow”.

Airflow carries moisture that impacts a materials long-term performance (serviceability) and structural integrity (durability). Airflow also affects building behavior in a fire (spread of smoke and other toxic gases, supply of oxygen), indoor air quality (distribution of pollutants and location of microbial reservoirs) and thermal energy use. One of the key strategies in the control of airflow is the use of air barriers.

Air barriers are systems of materials designed and constructed to control airflow between a conditioned space and an unconditioned space. The air barrier system is the primary air enclosure boundary that separates indoor (conditioned) air and outdoor (unconditioned) air. In multi-unit/townhouse/apartment construction the air barrier system also separates the conditioned air from any given unit and adjacent units. Air barrier systems also typically define the location of the pressure boundary of the building enclosure.

At SoCal Cleaning and Insulation, we use 3M Air and Vapor Barrier.


  • Impermeable to air, moisture, vapor and water
  • Excellent adhesion to concrete, concrete block, anodized aluminum, galvanized metal, plywood and most exterior gypsum boards
  • Multi-layer elastomeric film self-seals to prevent moisture intrusion
  • Apply at surface temperatures as low as 0°F (-18°C) or as high as 150°F (66°C)
  • Translucent film allows accurate placement of nail fasteners
  • Features measurement markings at 6 inch grid intersections for ease in alignment and cutting
  • Lighter weight than competitive products for easier handling and less fatigue
  • Adheres to damp surfaces that have not yet absorbed water, like metals, glass and plastics
  • Compatible with many building sealants