Vapor Permeable Air Barrier Products
As with all air barrier systems, vapor permeable air barrier products are designed to control the flow of air into and out of the building envelope. Air barrier benefits are substantial – they protect the long-term integrity of the building, reduce energy consumption from the building’s HVAC system, and help protect the health and safety of the building’s occupants by limiting the moisture intrusion that can cause mold growth.
So how do you know if your project needs vapor permeable air barrier products, or a non-vapor permeable air barrier solution? The building envelope experts at Henry Company have been helping designers and contractors decide exactly that for over 30 years. Each type of Henry air barrier product delivers exceptional, time-tested performance, but deciding which type is right for your build starts with an understanding of what each type is designed to do.
Vapor Permeable Air Barriers
Vapor permeable air barrier products will limit the intrusion of both air and bulk water while letting water vapor pass through the membrane. This vapor permeability helps prevent moisture from being trapped in the wall assembly.
In cold weather locations, keeping insulation and other wall assembly materials dry helps prevent the repeated freezing and thawing that reduces energy efficiency and can result in mold or algae growth. It all depends on the dew point and temperature fluctuations in your climate zone. In locations where trapped moisture is a high risk, vapor permeable air barrier products are generally the preferred choice.
Non-Vapor Permeable Air Barriers
Unlike vapor permeable products, non-vapor permeable air barriers are designed to allow almost no passage of water vapor through the membrane. Again, depending on the climate zone and weather conditions, this water vapor resistance can be highly beneficial.
For example – in warmer locations with heavy rainfall, robust bulk water resistance is essential and may require a non-vapor permeable membrane solution. Also, acrylic coatings and self-adhered sheets, non-vapor permeable air barriers tend to be more water resistant than their vapor permeable products.
Henry Vapor Permeable Air Barrier Products
Accordingly, being aware of the climate-related risks to the wall assembly should guide your decision to select either a vapor permeable or non-vapor permeable air barrier system. Henry experts can help you choose, and if you need a vapor permeable solution, Henry has several proven fluid and sheet applied options, including:
This fluid applied vapor permeable air barrier can be spray-, roll- or brush-applied on a wide range of substrates (including damp concrete) in temperature as low as 20°F (-6°C). Air-Bloc® 17MR cures to a tough, monolithic rubber-like membrane. Its proprietary fire-resistant technology provides superior fire performance with ASTM E1354.
This fluid applied vapor permeable air barrier is a UV-resistant elastomeric membrane suitable for most construction surfaces, including block, concrete, stone, wood and metal. Installed with a trowel or spray equipment, Air-Bloc® 33MR cures to a tough, monolithic, rubber-like membrane that resists air leakage and UV radiation.
This self-adhered vapor permeable air barrier membrane features a patented adhesive technology with split-back poly-release film for fast, easy installation. Blueskin® VP160 will fully adhere to substrates in a weatherboard method without mechanical attachment.
Look to Henry for air barrier advice
Backed by more than three decades of air barrier manufacturing experience, Henry Company can help you choose from a broad portfolio of both vapor permeable air barrier products and non-vapor permeable air barrier products. Our trusted building envelope experts can help you weigh all the pros and cons of which air barrier system type will best for your next build.