Air Barrier Products and Purposes

In simplest terms, air barrier products help manage the movement of air between the conditioned and unconditioned spaces in a building. This makes air barriers a key part of the building envelope, as they essentially keep the outside of the building out, and the inside of the building in.

By managing airflow in this way, air barriers protect the long-term health of the building and prevent moisture-induced problems. They also make buildings more energy efficient and comfortable for residents by eliminating drafts and controlling the moisture that can lead to mold growth and compromised air quality.

Air barriers support energy efficiency

According to the U.S. Department of Energy, buildings are responsible for about 40% of the primary energy consumed in the United States, 35% of which is dedicated to HVAC (heating, ventilation and air conditioning) demands.

The good news, according to the National Institute of Standards and Technology (part of the U.S. Department of Commerce) is that air barriers can shrink a building’s HVAC energy consumption by 30%, even in the hottest and coldest climate zones.

Air barriers prevent problems

Unmanaged or uncontrolled airflow can have several costly consequences for both building integrity and air quality. That’s because uncontrolled airflow brings with it uncontrolled moisture that can lead to condensation in the wall assembly.

Moist insulation and wall assembly materials lead to a cycle of freezing and thawing which in turn can reduce a building’s thermal resistance and drive energy costs. Over time, any dampness in the wall assembly can result in the growth of mold or algae, worsening indoor air quality and risking occupant health. Remediation efforts can be labor intense and expensive.

Air barrier products are systems

While an air barrier is often thought of as a single product, it’s more accurate to think of it as a system of products. An air barrier system includes the air barrier membrane, plus the primers, flashings, adhesives and sealants used with it to achieve an airtight plane around the building.

But because they form a complete system, air barrier products must be chemically compatible. Installing an air barrier membrane with chemically incompatible adhesives or sealants can lead to catastrophic product failures. Unfortunately, such failures may not be apparent until long after the wall assembly and building envelope is finished, when the fixes will be very costly.

Air barrier product types

The two basic types of air barrier systems include self-adhered sheet air barriers and fluid-applied air barriers. Depending on project requirements, each system has its own specific characteristics.

Self-adhered sheet air barriers don’t require mixing or spray equipment. They also ensure an even membrane thickness and can cover gaps or cracks without additional detailing. They may, however, require lap sealing, and installers must be careful to avoid bubbles or wrinkles when applying the sheets.

Fluid-applied air barriers can be sprayed, rolled or troweled onto the wall surface without any seams. Spray application is ideal for uneven substrates and complicated architectural details. Plus, many fluid-applied air barriers will cure in hours, further speeding installation. Installers must be careful to apply the membrane at the proper thickness and avoid over spraying.

Together with our expert advice, fully compatible air barrier products and systems from Henry can help ensure your air barrier system delivers the energy efficiency and protection it should. If you have questions, please don't hesitate to schedule a meeting with one of our reps today.