When Wall Ties Fail: The Hidden Risk Behind Step-Cracking Walls

Take a close look at the image below. Those dramatic step-cracks running diagonally through the brickwork are not just cosmetic defects, they’re a classic warning sign of failing or corroded wall ties. Left untreated, this type of damage can lead to the outer leaf of a cavity wall bowing, bulging or even collapsing.

Why Wall Ties Are So Important

Cavity walls are built in two layers (inner and outer leaf) separated by a cavity. Wall ties are the unseen connectors linking these two leaves, ensuring they act as a single, stable structure. When these ties weaken or break, the outer layer is left unsupported, significantly reducing wind resistance and structural stability.

Modern stainless-steel wall ties are designed to last decades, but many older properties still rely on mild steel ties installed in the 1930s–1980s, which are far more prone to corrosion.

How Wall Tie Failure Happens

• Corrosion Over Time
  Mild steel wall ties, especially those installed before the 1980s, corrode as their protective coatings break down.

• Damp Cavity Wall Insulation
  Moist insulation traps water against ties, speeding up corrosion.

• Exposure to Weather
  Exposed areas suffer more severe conditions.

As corrosion develops, the metal expands. Developing rust takes up a greater volume than the original steel, which forces the surrounding mortar to crack and lift. This expansion is exactly what causes the classic “step-cracking” pattern seen in the image.

Why Early Detection Matters

By the time cracks are visible on the outside of a wall, the hidden ties may have been failing for years. Early detection through a professional wall tie survey allows remedial work to be carried out before the wall loses its stability.

CavClear’s Approach to Wall Tie Remediation

When wall tie failure is confirmed, we follow a proven three-step process:

1. Install New Stainless-Steel Remedial Ties
   We drill precision holes and insert corrosion-resistant stainless-steel wall ties to restore the connection between the inner and outer leaves. These ties are engineered for exceptional durability and long-term stability.

2. Isolate Old Ties
   The old corroded ties are either removed or isolated with special sleeves to prevent further rust expansion and cracking of the brickwork.

3. Stabilise and Repair Brickwork
   We carry out targeted masonry repairs to restore appearance and ensure the wall is structurally sound.

This approach prevents further deterioration, strengthens your walls, and often saves the homeowner the much larger cost of rebuilding sections of the property.

Key Warning Signs of Wall Tie Failure

• Step-cracking in mortar joints (especially diagonally).

• Bulging or bowing walls.

• Movement around window or door openings.

• Properties built before the use of modern stainless-steel ties.

Book a Wall Tie Survey with CavClear

If you’ve noticed step-cracks, bulging walls, or own a property built before the 1980s, a wall tie survey is the most effective way to protect your home. Contact CavClear today to book your professional wall tie survey and protect your home from hidden structural risks.