Air leaks carry water vapor through wall cavities causing condensation during the winter.

Air barriers versus vapor retarder’s

An air barrier is a building assembly that resists air leakage between indoors and outdoors. Warm, moist air from the home can carry moisture rapidly from a moisture source into the building cavities where damaging condensation can occur. Air barriers are important to stopping the flow of moist air into building cavities. Sealing all penetrations in the surface of the building creates an air barrier capable of stopping moist-air infiltration and exfiltration during winter. Vapor barriers or vapor retarder’s have a different function — they resist vapor diffusion, which is a slower process than moisture leaking in and out with moist air.

Air sealing

The goal of air sealing is to create a continuous air barrier on all sides of the building.
  • Identify and plug air leaks like plumbing chases, chimney enclosures, and wire holes.
  • Install gaskets on all outlets and switches.
  • Find large air leaks in floors and ceilings and seal them.
  • Seal window and door frames;
  • Patch holes and cracks in ceilings and walls.
  • Seal the floor/wall junction.

Air barriers and water-resistive barriers

It is common to install a water resistive barrier on the exterior of a wood frame building. The water resistive barrier can serve as both the air barrier and water barrier. Air barriers and water resistive barriers, like Tyvek, are vapor-permeable and allow water vapor to escape from building cavities to keep those building cavities dry. Many new homes employ polyethylene as a vapor barrier in court climates. Vapor barriers stop almost all water vapor diffusion. Energy specialists call materials like plywood and OSB vapor retarder’s in these materials resist vapor diffusion rather than stopping vapor diffusion completely. The exterior air barrier, like Tyvek®, is a good option for existing buildings when you replace siding. Don’t neglect flashing around windows and doors, which if properly installed prevents water leakage into the wall cavity. Window flashing flaws have cost mistakes billions of dollars in damage to modern homes. For more information on air barriers, vapor retarder’s, and water resistive barriers see the following publications. Residential Energy: Cost Savings and Comfort for Existing Buildings, Saturn Energy Auditor Field Guide,

Air barriers versus vapor retarder’s

An air barrier is a building assembly that resists air leakage between indoors and outdoors. Warm, moist air from the home can carry moisture rapidly from a moisture source into the building cavities where damaging condensation can occur. Air barriers are important to stopping the flow of moist air into building cavities. Sealing all penetrations in the surface of the building creates an air barrier capable of stopping moist-air infiltration and exfiltration during winter. Vapor barriers or vapor retarder’s have a different function — they resist vapor diffusion, which is a slower process than moisture leaking in and out with moist air.

Air sealing

The goal of air sealing is to create a continuous air barrier on all sides of the building.
  • Identify and plug air leaks like plumbing chases, chimney enclosures, and wire holes.
  • Install gaskets on all outlets and switches.
  • Find large air leaks in floors and ceilings and seal them.
  • Seal window and door frames;
  • Patch holes and cracks in ceilings and walls.
  • Seal the floor/wall junction.

Air barriers and water-resistive barriers

It is common to install a water resistive barrier on the exterior of a wood frame building. The water resistive barrier can serve as both the air barrier and water barrier. Air barriers and water resistive barriers, like Tyvek, are vapor-permeable and allow water vapor to escape from building cavities to keep those building cavities dry. Many new homes employ polyethylene as a vapor barrier in court climates. Vapor barriers stop almost all water vapor diffusion. Energy specialists call materials like plywood and OSB vapor retarder’s in these materials resist vapor diffusion rather than stopping vapor diffusion completely. The exterior air barrier, like Tyvek®, is a good option for existing buildings when you replace siding. Don’t neglect flashing around windows and doors, which if properly installed prevents water leakage into the wall cavity. Window flashing flaws have cost mistakes billions of dollars in damage to modern homes. For more information on air barriers, vapor retarder’s, and water resistive barriers see the following publications. Residential Energy: Cost Savings and Comfort for Existing Buildings, Saturn Energy Auditor Field Guide,

Air barriers versus vapor retarder’s

An air barrier is a building assembly that resists air leakage between indoors and outdoors. Warm, moist air from the home can carry moisture rapidly from a moisture source into the building cavities where damaging condensation can occur. Air barriers are important to stopping the flow of moist air into building cavities. Sealing all penetrations in the surface of the building creates an air barrier capable of stopping moist-air infiltration and exfiltration during winter. Vapor barriers or vapor retarder’s have a different function — they resist vapor diffusion, which is a slower process than moisture leaking in and out with moist air.

Air sealing

The goal of air sealing is to create a continuous air barrier on all sides of the building.
  • Identify and plug air leaks like plumbing chases, chimney enclosures, and wire holes.
  • Install gaskets on all outlets and switches.
  • Find large air leaks in floors and ceilings and seal them.
  • Seal window and door frames;
  • Patch holes and cracks in ceilings and walls.
  • Seal the floor/wall junction.

Air barriers and water-resistive barriers

It is common to install a water resistive barrier on the exterior of a wood frame building. The water resistive barrier can serve as both the air barrier and water barrier. Air barriers and water resistive barriers, like Tyvek, are vapor-permeable and allow water vapor to escape from building cavities to keep those building cavities dry. Many new homes employ polyethylene as a vapor barrier in court climates. Vapor barriers stop almost all water vapor diffusion. Energy specialists call materials like plywood and OSB vapor retarder’s in these materials resist vapor diffusion rather than stopping vapor diffusion completely. The exterior air barrier, like Tyvek®, is a good option for existing buildings when you replace siding. Don’t neglect flashing around windows and doors, which if properly installed prevents water leakage into the wall cavity. Window flashing flaws have cost mistakes billions of dollars in damage to modern homes. For more information on air barriers, vapor retarder’s, and water resistive barriers see the following publications. Residential Energy: Cost Savings and Comfort for Existing Buildings, Saturn Energy Auditor Field Guide,

Air barriers versus vapor retarder’s

An air barrier is a building assembly that resists air leakage between indoors and outdoors. Warm, moist air from the home can carry moisture rapidly from a moisture source into the building cavities where damaging condensation can occur. Air barriers are important to stopping the flow of moist air into building cavities. Sealing all penetrations in the surface of the building creates an air barrier capable of stopping moist-air infiltration and exfiltration during winter. Vapor barriers or vapor retarder’s have a different function — they resist vapor diffusion, which is a slower process than moisture leaking in and out with moist air.

Air sealing

The goal of air sealing is to create a continuous air barrier on all sides of the building.
  • Identify and plug air leaks like plumbing chases, chimney enclosures, and wire holes.
  • Install gaskets on all outlets and switches.
  • Find large air leaks in floors and ceilings and seal them.
  • Seal window and door frames;
  • Patch holes and cracks in ceilings and walls.
  • Seal the floor/wall junction.

Air barriers and water-resistive barriers

It is common to install a water resistive barrier on the exterior of a wood frame building. The water resistive barrier can serve as both the air barrier and water barrier. Air barriers and water resistive barriers, like Tyvek, are vapor-permeable and allow water vapor to escape from building cavities to keep those building cavities dry. Many new homes employ polyethylene as a vapor barrier in court climates. Vapor barriers stop almost all water vapor diffusion. Energy specialists call materials like plywood and OSB vapor retarder’s in these materials resist vapor diffusion rather than stopping vapor diffusion completely. The exterior air barrier, like Tyvek®, is a good option for existing buildings when you replace siding. Don’t neglect flashing around windows and doors, which if properly installed prevents water leakage into the wall cavity. Window flashing flaws have cost mistakes billions of dollars in damage to modern homes.

For more information on air barriers, vapor retarder’s, and water resistive barriers see the following publications.

Residential Energy: Cost Savings and Comfort for Existing Buildings,

Saturn Energy Auditor Field Guide, For more information on air barriers, see the following courses.

Air Barrier Basics (Mini Course – Individual Purchase Course)