Cavity wall terminology — name of the inner section In a cavity wall consisting of two parallel leaves separated by an air gap and tied together, what is the inner section (the leaf on the room side) generally called?

Introduction / Context:
Cavity walls are formed by two thin masonry leaves with a cavity in between, connected by metal or polymer ties. The system improves thermal insulation, moisture resistance, and sometimes sound attenuation. Correct naming of the components is important for detailing ties, damp-proof courses, and finishes.

Given Data / Assumptions:

• Two masonry leaves: one external (weather face) and one internal (room face).
• Leaves are linked by wall ties across the cavity.
• Question asks the name of the inner section.

Concept / Approach:
The two parts of a cavity wall are called “leaves.” The inner portion is the inner leaf; the outer portion is the outer leaf. A buttress, pilaster, or pillar denotes projecting or isolated structural elements and is unrelated to the twin-leaf configuration. While the most precise term is “inner leaf,” some texts and schedules refer to each as a “leaf wall.” Given the options provided, “leaf wall” denotes the correct component.

Step-by-Step Solution:

Verification / Alternative check:
Standard details label the interior masonry leaf supporting internal finishes and services as the “inner leaf.”

Why Other Options Are Wrong:

• buttress/pilaster/pillar: represent projecting or columnar supports, not the inner leaf of a cavity wall.
• none of these: incorrect because “leaf wall” corresponds to the intended component here.

Common Pitfalls:
Confusing general masonry terms with cavity wall nomenclature; overlooking that both sides are called leaves.

Final Answer:
leaf wall