While a cavity in a wall may seem disastrous, a cavity wall is an architectural innovation offering exceptional benefits. Let’s understand this concept here in this infographic.
What is a Cavity Wall?
A cavity wall comprises two parallel masonry walls (leaves) separated by a gap (cavity). The outer wall is made of brick, while the inner wall can be made of concrete blocks, bricks, or reinforced concrete. The leaves are tied together with metal or terra-cotta ties for structural stability. It provides moisture control, thermal insulation, soundproofing, and structural efficiency.
Advantages of Cavity Walls
- Moisture Resistance: Prevents dampness by keeping the inner leaf dry.
- Thermal Insulation: Air in the cavity minimizes heat transfer, keeping interiors warm in winter and cool in summer.
- Sound Insulation: Acts as a sound barrier by absorbing external noise.
- Efflorescence Prevention: Protects walls from salt deposits caused by dampness.
- Cost Efficiency: Cheaper than thick solid walls of similar damp resistance.
- Fire Resistance: Offers robust fire protection.
Disadvantages of Cavity Walls
- Requires skilled labor and supervision.
- Risk of moisture infiltration if improperly insulated.
- Decreases usable interior space.
- Potential issues with wall tie corrosion and thermal bridging.
Construction Insights
- Wall Ties: Positioned 90 cm horizontally and 30-45 cm vertically for stability.
- Ventilation: Air bricks ensure proper ventilation in the cavity.
- Openings: Vertical damp-proof courses seal cavity edges at doors/windows to prevent damp ingress.
