October 18, 2023

How do Fluid-Applied Air Barriers Contribute to Air Quality Inside of a Building?

Fluid-applied air barriers are a critical component of modern building design and construction. They provide multiple benefits, including improved energy efficiency, moisture management, and building durability. In addition, fluid-applied air barriers also significantly contribute to improved indoor air quality (IAQ) within buildings. For this week’s blog post, we take a look at six ways in which fluid-applied air barriers can significantly contribute to energy efficient buildings with improved indoor air quality (IAQ), and extended building façade durability.

  1. Air Leakage Prevention:  Fluid-applied air barriers together with installation accessories like liquid-applied flashing and joint compounds, flexible bituminous and butyl self-adhering sheet flashings, pre-formed silicone transition membranes, and joint sealants combine to form a continuous, airtight seal over the vertical opaque building enclosure and tie into door and window frames, roofing, and below-grade waterproofing. The resulting assembly prevents passage of airborne moisture vapor, particulate matter, and odors from the outdoor environment into interior conditioned spaces. So, properly designed and installed air barriers enhance occupant health and comfort.
  2. Bulk Water Control: Water penetration into exterior wall cavities and interior areas is the root cause of structural degradation and occupant discomfort. Of air, thermal, vapor and water control layers, water is most critical. In most cases, there is alignment between water resistive barrier and air barrier design criteria and installation parameters. Therefore, most fluid-applied air barriers are capable of performing a dual function of keeping air and water out of wall cavities and building spaces which satisfies the most basic shelter need.
  3. Temperature Regulation: By performing as a barrier to air leakage, air barriers prevent infiltration of air having a significant temperature delta from that of the building interior. In other words, in heating climates, air barriers prevent cold outdoor air from mixing with indoor conditioned air. Conversely, in cooling climates, air barriers prevent hot and humid air from compromising air conditioned spaces. Installation of a continuous air barrier prevents draftiness and allows more economical sizing and operation of building heating, ventilating, and air conditioning (HVAC) equipment thereby resulting in lower utility bills.
  4. Reduced Outdoor Pollutants: By filling and closing off joints, gaps, and other breaches in the building enclosure, fluid-applied air barriers prevent entry of outdoor pollutants including particulate matter, pollen, and airborne odors and contaminants. This is especially beneficial for individuals with respiratory conditions, allergies, or sensitivities to outdoor air quality.
  5. Energy Conservation:  Practically speaking, reduced energy consumption and the associated utility cost savings are among the leading benefits of air barriers and make them a highly sustainable design strategy. In sealed buildings, HVAC systems don’t have to be oversized to compensate for leaky building envelopes. Heating and cooling systems don’t run as long to keep up with changes in humidity and air temperature. Furthermore, as the outdoor-indoor separator, many fluid-applied air barriers minimize the introduction of VOC’s (volatile organic compounds) into the indoor air thus contributing to enhanced indoor air quality.


In conclusion, fluid-applied air barriers are a vital component of building design and construction for maintaining enhanced energy efficiencies, building façade durability, and indoor air quality. By creating a tight building envelope and controlling the flow of air and moisture vapor, fluid-applied air barriers aid in minimizing the introduction of outdoor pollutants, moisture, air flow, and temperature fluctuations from affecting the indoor environment. This results in healthier, comfortable, energy-efficient indoor spaces for occupants and building owners.


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