Table of Contents
- Why choose WGYC Air Barrier?
- What is an air vapour barrier?
- What is the Purpose of an Air Barrier?
- What exactly is the distinction between an air barrier and a vapour barrier?
WGYC uses the NaturaSeal Air Barrier NS-A250 product line for vapour barrier solutions, used in high and low permeability formulations. It is UV stable, waterproof, and resistant to vapour and weather. All stick naturally to the most commonly used substrates, including OSB, Plywood, exterior gypsum, concrete, brass, and aluminum. Both have a Class A fire-resistance rating. They have a smooth membrane and are compliant with all cladding systems and face-sealed assemblies such as stucco and EIFS.
An air barrier material is built to create a continuous plane around a building to avoid unrestricted airflow in and out of the building envelope and resists air leakage.
Mechanically fastened building covers, adhesive membranes, fluid-applied materials, insulating board stock, non-insulating board stock, spray polyurethane foam, poured concrete, metal, glass, and various other materials can all be used as air barriers.
However, regardless of the material used, all air barriers must be:
- Impermeable to airflow.
- Continuous over the whole building enclosure or continuous over the enclosure of any given unit.
- Capable of withstanding the forces that could be applied to them before and after construction.
- Durable over the building’s projected lifetime.
Remember that there are two forms of air barriers: internal and external, and although they both have identical functions, one complements and improves the effectiveness of the other. Interior air barriers prevent infiltration of a home’s interior air into the wall cavity and attic, restrict the ability of wet indoor air to penetrate the wall cavity during the heating season, and reduce convection losses inside walls.
Exterior air barriers regulate the penetration of outside air into the wall cavity and attic, restrict the ability of wet outside air to penetrate the wall cavity during the cooling season, and avoid wind-washing of wall insulation. It is best to mount all types of air barriers so that the advantages of one do not outweigh the benefits of the other.
An efficient air barrier’s function is to control the indoor environment by preventing the movement of air and the moisture it carries between the interior and exterior of a home. An air barrier must also be able to withstand the effects of air pressure variations. Stopping air from carrying moisture to the interior of a wall assembly is essential because as warm vapour comes into contact with cold interior surfaces, the vapour condenses and becomes liquid. Air barriers, in essence, mitigate or limit heat loss and gain through conduction, convection, and radiation.
Thermal conduction is the movement of hotter molecules into colder molecules. The successful R-value of a building’s wall structure is its resistance to conduction.
Thermal convection is the movement of heat energy from a warmer to a colder environment through the flow of fluids.
Thermal radiation, which is essentially the sun’s radiation, uses electric waves to transfer heat from hot spots to cold spaces.
- Impermeable to airflow
- Continuous over the entire building enclosure
- Durability over the home’s projected lifespan
- The ability to withstand the forces that may be applied to them during and after building.