What is a primary characteristic of cellular glass insulation?

Cellular glass insulation is known for its impermeability to moisture, making it an excellent choice for various applications, especially in environments where moisture could pose a significant threat to insulation performance. This characteristic is primarily due to its closed-cell structure, which ensures that water vapor or liquid water cannot penetrate the material. As a result, cellular glass insulation helps to prevent mold and mildew growth, maintains thermal performance, and broadens its usability in specialized construction applications, including below-grade and roofing systems.

In addition to being moisture-resistant, cellular glass is also non-combustible and has a high compressive strength, which adds to its appeal as a durable insulation option. The other characteristics listed do not accurately describe cellular glass insulation; for example, it is not flammable, it has a relatively high R-value compared to traditional insulation materials, and it is not typically used in loose fill applications. The unique combination of moisture resistance, thermal performance, and fire safety sets cellular glass insulation apart in the construction industry.