Cavity walls — primary functions in building construction A cavity wall consists of two leaves separated by an air gap or insulated cavity and connected by ties. For what purposes are cavity walls generally provided?

Introduction / Context:
Cavity walls are a widely used envelope strategy in temperate and humid climates. By separating the external and internal leaves with an air space (and sometimes adding insulation), cavity walls improve building performance and durability compared to single-leaf solid walls.

Given Data / Assumptions:

• Two masonry leaves with a cavity and stainless/galvanized ties.
• Provision for damp-proofing, weep holes, and ventilation of the cavity if required.
• Focus on typical benefits, not specialized variants.

Concept / Approach:

The cavity interrupts conductive and moisture paths and can host insulation batts/boards. Thermal resistance increases, surface temperatures are stabilized, and interstitial condensation risks can be managed. The air gap and decoupled leaves also attenuate airborne noise, and the cavity acts as a barrier to rain penetration with drainage to the exterior via weep holes.

Step-by-Step Solution:

Verification / Alternative check:

Building codes and façade design guides endorse cavity walls for driving rain exposure zones and for meeting energy codes with cavity insulation systems.

Why Other Options Are Wrong:

• Each of (a)–(c) is correct; hence the combined answer is “All of the above”.

Common Pitfalls:

• Bridging the cavity with mortar droppings or continuous ties that create thermal/damp bridges.
• Omitting weep holes or cavity trays over openings, causing moisture problems.

Final Answer:

All of the above.