Which of the following materials are commonly used as air barriers?

The correct choice highlights materials specifically designed and commonly recognized for their effectiveness as air barriers in building construction. Building wraps, rigid foam insulation, spray foam, and self-adhering membranes are all engineered for air impermeability and are frequently applied to prevent air leakage in a variety of building assemblies.

Building wraps are often used as a protective layer that allows moisture vapor to escape while preventing air from penetrating the structure. Rigid foam insulation serves dual purposes, providing thermal resistance while also acting as an air barrier when installed properly. Spray foam creates a continuous seal that fills gaps and cracks, making it an effective option for air sealing. Self-adhering membranes are applied directly to surfaces and form a moisture-resistant barrier while also impeding air movement.

In contrast, the other material options listed do not inherently serve as effective air barriers. Wood, glass, concrete, brick, metal, and asphalt may play roles in building construction but do not provide the same level of air sealing performance as the materials indicated in the correct choice. Gypsum board, paint, and plaster, while important for interior finishes, often allow some air movement and are not primarily designed for air barrier applications. Understanding the characteristics and intended uses of these materials is crucial for effective air barrier design and implementation