What Is an Air Barrier in Construction?

Introduction

In the realm of construction, ensuring the energy efficiency and comfort of buildings is a primary concern. An essential component in achieving these goals is the air barrier. This article will delve into the concept of air barriers in construction, their importance, and the various types used in the industry.

Understanding Air Barriers in Construction

Definition and Purpose

An air barrier in construction is a system or material designed to control the flow of air between the interior and exterior of a building. Its primary purpose is to prevent the uncontrolled infiltration and exfiltration of air, which can lead to energy loss, moisture problems, and reduced indoor air quality. By creating a continuous barrier, it helps maintain a comfortable and energy-efficient indoor environment.

Importance of Air Barriers

The significance of air barriers lies in their ability to enhance a building’s thermal performance. By minimizing air leakage, they reduce the demand on heating and cooling systems, leading to lower energy consumption and costs. Additionally, air barriers play a crucial role in preventing moisture from entering the building envelope, which can cause mold growth and structural damage.

Types of Air Barrier Systems

Sheet Membranes

Sheet membranes are flexible materials, such as rubberized asphalt or polyethylene, used to create an air barrier. They are applied to the exterior of the building envelope and are known for their durability and resistance to air and moisture.

Fluid-Applied Membranes

Fluid-applied membranes are coatings that are sprayed or rolled onto surfaces to form an air barrier. They offer flexibility in application and can conform to irregular shapes, making them suitable for complex building designs.

Board Stock

Board stock air barriers consist of rigid panels made from materials such as extruded polystyrene or polyisocyanurate. These panels are installed on the exterior of the building and provide both insulation and air barrier properties.

Spray Foam Insulation

Spray foam insulation serves as both an insulating material and an air barrier. It is sprayed onto surfaces, where it expands and hardens, creating a continuous barrier that seals gaps and cracks.

Conclusion

Air barriers are a crucial component in the construction of energy-efficient and comfortable buildings. By controlling air flow and preventing moisture infiltration, they contribute to the overall performance and durability of the building envelope. Understanding the different types of air barrier systems and their applications allows construction professionals to make informed decisions in designing and constructing buildings that meet high standards of energy efficiency and indoor air quality.