A weather barrier is part of the wall assembly; it prevents the passage of moisture, rain and wind through critical areas of the walls and roof, and protects vulnerable building components from deterioration. …
What is a weather resistant barrier?
Weather-resistive barriers are a part of exterior wall systems that protect building materials from exterior water penetration. They perform like a shell for buildings—liquid water that has penetrated the exterior finish does not pass through, yet water vapor can escape.
What is an air barrier in construction?
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.
Is air barrier the same as vapor barrier?
A vapor barrier is designed to restrict the flow of water vapor through a material, just the same as an air barrier material restricts the flow of air through a material.
What is the purpose of a vapor barrier?
The purpose of vapour barriers
A vapour barrier is an important component in building construction. Its purpose is to help prevent water vapour from reaching building walls, ceilings, attics, crawlspaces or roofs, where it can condense and cause building materials to rot or grow mould.
Is Tyvek a weather resistant barrier?
Tyvek® HomeWrap®* and the ZIP System® are weather resistant barriers (WRB) applied under the siding of a home or commercial building.
What is a good air barrier?
A variety of materials make good air barriers. Some of the most common are drywall, plywood, polyethylene sheeting, oriented strand board (OSB) sheathing, and rigid foam insulation. Although air cannot leak through these materials, air can travel through openings and seams.
What are the 5 basic requirements of air barrier systems?
The five essential components of an air barrier:
- Continuous: no gaps, cracks or openings.
- Impermeable to the leakage of air.
- Rigid: supported in both directions from wind pressure.
- Durable: must last the life of the building.
- Repairable: access for repair if damaged.
Is concrete a good air barrier?
A wide variety of materials make good air barriers, including poured concrete, glass, drywall, rigid foam insulation, plywood, and peel-and-stick rubber membrane. … To make a good air barrier, a material not only needs to stop air flow; it also needs to be relatively rigid and durable.
Is vapor barrier required?
A vapor barrier is likely required if the building is cladded with absorptive material and if the structure is in United States climate zones 4C, 5 through 8. If you are building in a colder climate, check local laws or consult with your architect if a vapor barrier is required.
Where should vapor barrier be installed?
Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates. In existing spaces, oil-based paints or vapor-barrier latex paints offer an effective moisture barrier.
Do interior walls need vapor barrier?
Normally interior walls do not require a vapor barrier, but there are some situations where it is highly recommended. … The paint acts as a vapor barrier as well. A continuous plastic vapor barrier behind the drywall will protect the interior walls of these areas from water damage.
Is Tyvek a good air barrier?
When Tyvek® is used under sheathing, it functions only as an air barrier, and does not protect the sheathing as a secondary weather barrier. Tyvek® has been used directly over studs where there is no sheathing, although use of sheathing is a highly recommended building practice.
Where is an air barrier used?
Air barriers keep outside and inside air out of the building enclosure. Air barriers can be located anywhere in the building enclosure—at the exterior surface, the interior surface, or at any location in between. In heating climates, interior air barriers control the exfiltration of interior, often moisture-laden, air.