Cavity Wall

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Cavity Wall

What is Cavity Wall?

Cavity Wall, A wall construction with an air space between two separate wall layers for improved insulation and moisture control

Description

Cavity wall is a wall construction method that incorporates an air space or cavity between two separate wall layers, typically consisting of an outer wythe of masonry and an inner wythe of masonry or other materials. This construction technique provides improved thermal insulation, moisture control, and structural performance compared to solid wall construction while enabling the use of different materials for interior and exterior wall functions.

Purpose includes improving thermal performance, controlling moisture infiltration, enabling material optimization, and providing structural efficiency. Cavity wall construction addresses multiple building performance requirements through intelligent design and material selection.

Construction consists of outer wythe for weather protection, inner wythe for structural support, cavity space for insulation and drainage, and ties connecting the two wythes. Each component serves specific functions while contributing to overall wall performance.

FAQs

  • What’s the difference between cavity walls and solid walls?

    Cavity walls include an air space between layers for insulation and drainage, while solid walls are continuous; cavity walls generally perform better.

  • How wide should the cavity be?

    Typically 2–4 inches depending on insulation requirements and structural considerations, with wider cavities accommodating more insulation.

  • Do cavity walls need special ties?

    Yes, corrosion-resistant wall ties designed for cavity construction are required to maintain structural connection while preserving cavity benefits.

  • Can existing solid walls be converted to cavity walls?

    Conversion is difficult and expensive; adding exterior or interior insulation is usually more practical.

  • What insulation works best in cavity walls?

    Rigid foam, mineral wool, or spray foam can all be used, depending on climate and performance requirements.

  • How do you prevent moisture problems in cavity walls?

    By using proper flashing, weep holes, drainage details, and vapor management strategies.

  • Are cavity walls more expensive than solid walls?

    They typically have higher initial costs but lower operating costs due to improved energy performance.

Fun Fact

Fun Fact: Cavity wall construction was first developed in England in the 1860s to address moisture problems in solid masonry walls, revolutionizing masonry construction.

CSI Code

04 20 00

NAHB Code

420