Air & Vapor Barrier

Air & Vapor Barriers control the unintended movement of air and moisture into and out of a building enclosure.

Air / Vapor barrier systems are comprised of a number of materials which are assembled together to provide a complete barrier to air and moisture leakage through the building enclosure. The building enclosure includes all six sides of the building and may included separations within a building. This system essentially “wraps” the building shell and ensures that it protects the building from the effects of air and moisture leakage. Air and moisture leakage can have detrimental effects on how a building functions and reduces the life span of a building.

A properly functioning air barrier system provides a barrier against both the air leakage and the diffusion of air caused by wind, stack and mechanical equipment pressures.

When conditioned air leaks out of a building and unconditioned air and moisture leak into a building we must then use additional energy to then condition this air. Air leakage can result in an increased use in energy costs of up to 30-40% in heating climates and 10-15% in cooling climates.

Buildings which have a properly installed air / vapor barrier system can operate properly with a smaller HVAC system as the mechanical engineer does not have to compensate for a leaky building. In many cases, the reduction in mechanical equipment size and cost can offset the cost of the air barrier system.

Air barrier systems also provide a barrier to pollutants entering either the building or the building enclosure. Water vapor, suspended particulates, dust, insects, smells, etc are all pollutants which we want to keep out of either the building in general or the building enclosure. Water vapors that leak into the building enclosure (from the inside in heating climates and from the outside in cooling climates) can condensate and form liquid water a key ingredient to corrosion and the potential development of mold

The Air Barrier Association of America (ABAA) was formed in Massachusetts with a view to “developing a professional Air barrier specialty trade and industry dedicated to the installation of effective air barrier systems in buildings on a national scale”. Some states are mandating air barriers in their energy codes. Air barriers can also contribute to earning points towards a LEED certification. Phoenix Bay State Construction is a proud member of ABAA and both our mechanics and management staff participate regularly in seminars and training courses aimed at maintaining the standards.

ABAA has grouped the Air Barrier materials into several types which are listed below; Phoenix Bay State Construction has the trained staff to provide the proper and certified installation of the following systems.

  • Self-Adhered Sheet Membranes
  • Fluid Applied Membranes
    • Non Foaming Liquids
    • Spray Polyurethane Foam
  • Mechanically Fastened Membranes
    • Boardstock
    • Film