What type of wall consists of two walls that act independently, separated by an air space of 2 inches or more?

Cavity masonry walls are designed with two separate walls, often referred to as leaves, which are separated by an air space of at least 2 inches. This configuration provides various advantages, including improved insulation, moisture control, and structural stability. The air space serves as a barrier to prevent moisture from penetrating the inner wall, protecting against the infiltration of water while allowing for ventilation. This design also enhances the energy efficiency of the building, as the insulation properties of the air gap contribute to temperature regulation.

In contrast, solid masonry walls consist of a single, thick wall with no air space, making them less effective in managing moisture and insulation. Reinforced masonry walls, while providing added strength through the inclusion of steel reinforcement, do not inherently involve the air space characteristic of cavity walls. Composite walls, on the other hand, are made up of different materials combined to form a single unit but do not have the same structural separation found in cavity masonry walls. Understanding these distinctions is crucial in selecting the appropriate wall type for specific construction needs and enhancing building performance.