What is an air barrier in construction and why is it important?

Building owners and designers can create a more sustainable and efficient building that is comfortable and healthy for occupants by carefully designing and installing an air barrier. But what is an air barrier in construction?

Simply put, an air barrier is a material or system that is designed to control the movement of air through the building envelope, or outer walls and roof of a building. Its primary purpose is to prevent drafts and air leakage, which can lead to energy loss, discomfort, and other problems.

There are several reasons why an air barrier is important in commercial construction:

1. Energy efficiency: An air barrier helps to prevent drafts and air leakage, which can lead to energy loss. By controlling the movement of air, an air barrier can help to reduce heating and cooling costs and improve the overall energy efficiency of the building.
2. Comfort: Air leakage can lead to drafts and uncomfortable temperatures in a building. An air barrier can help to create a more consistent and comfortable indoor environment.
3. Indoor air quality: An air barrier can help to prevent outdoor air from entering the building, which can improve indoor air quality.
4. Moisture control: When air enters a building, it can carry moisture with it, which can lead to moisture-related problems such as mold, rot, and structural damage. An air barrier helps to block the passage of moisture-laden air, which can help to protect the building from these types of problems.

Tips for selecting an air barrier system

When it’s time to choose an air barrier system for your next project, its important to consider some factors to make sure you are selecting the right system. While choosing between a fluid applied and self-adhered membrane is one factor, one must consider other factors, including:

• Climate zone – Climate conditions can most directly impact moisture mitigation and energy efficiency, but each climate zone presents unique challenges to air barrier system performance.
• Wall assembly design – What is the substrate onto which the air barrier will be applied? Are there complex design details, geometries, or rough surfaces?
• Where is the insulation located – is it all in the stud space, is it split between the stud space and the cavity, or is it all in the cavity? Finally, what about compliance with NFPA 285? Consideration of all of these factors is key to selecting the best air barrier for the building.
• Assess building details and penetrations – Are there lots of penetrations (windows, doors, holes, pipe penetrations, etc.), or are the walls fairly opaque? If there are a lot of window openings and a sheet membrane is the preferred window flashing, then it makes sense to use a sheet membrane in the field. If certain walls are relatively opaque, spraying a fluid-applied membrane will be very efficient.

So if you are wondering, “What is an air barrier in construction?”, consider reaching out to a Henry Representative to learn more today.