What is it?
Wall ties are metal components used to connect two leaves of a masonry wall, typically the outer brickwork and inner blockwork in a cavity wall. They allow the two leaves to work together structurally while maintaining a cavity for insulation and moisture control.
Wall ties are usually made from stainless steel or galvanized steel to resist corrosion and come in different profiles depending on cavity width, wall height, and exposure conditions. They are installed at regular vertical and horizontal spacings during masonry construction.
- 1Brick (external leaf)
- 2Wall Tie
- 3Cavity Insulation
- 4Block (internal leaf)
What does it do?
Wall ties transfer lateral loads between the outer and inner leaves, preventing bulging or separation of the wall.
Where is it used?
Wall ties are used wherever two masonry leaves need to be connected while maintaining a cavity, including:
- External cavity walls of houses and low-rise buildings
- Party walls in multi-residential developments
- Boundary walls with cavity construction
- Any masonry cavity wall where the leaves are separate and need to act together structurally
Types
Wall ties are manufactured in several forms depending on wall construction and performance requirements:
- Standard ties: Zig-zag or twist ties for general cavity walls.
- Heavy-duty ties: For high walls, exposed conditions, or walls with wider cavities.
- Insulated ties: Designed to minimise thermal bridging between inner and outer leaves.
- Adjustable ties: Can accommodate variable cavity widths.
Typical sizes
- Wall ties are generally 225–300 mm in length for standard cavity widths (50–100 mm) and 2.5–4 mm thick. Horizontal spacing is typically 450 mm, with vertical spacing of 450–600 mm. They are usually installed in staggered patterns, with extra ties at openings such as heads and sills.
How to specify
Key factors when specifying wall ties:
- Cavity width: Must match wall cavity to ensure proper installation.
- Material: Stainless steel for exposed locations or high-moisture environments; galvanized steel for internal walls or low-risk locations.
- Load requirements: Standard ties are sufficient for most domestic walls, heavy-duty ties may be required for taller or exposed walls.
- Thermal bridging: Consider insulated ties to reduce heat loss through the wall system.
- Compliance: Ties should meet relevant UK guidance such as BRE Digest 363 or equivalent.
Other considerations
Correct installation is essential to prevent wall bulging or separation. Additional ties may be needed at openings such as windows and doors. Misplaced or missing ties can compromise wall stability. Insulated ties may be preferred in highly energy-efficient constructions.
Interacting elements
Wall ties connect the inner and outer leaves of a cavity wall and work with other elements to ensure the wall functions correctly.
- Outer brick leaf - forming the visible external surface
- Blockwork - typically forming the inner structural leaf
- Cavity insulation - installed between the leaves
- Damp proof course (DPC) - preventing moisture rising through the wall
- Cavity trays - directing water out of the cavity
- Lintels - supporting masonry above openings
- Foundations - providing overall support for the wall structure