Do you know how important wall ties are to a building's structural integrity? These modest parts may fail over time and cause several structural problems. This article will examine the causes of wall tie failures as well as workable remedies for them.
Please don't hesitate to contact us for professional guidance and solutions if you believe your property may have wall tie problems by calling us on 07852 229017.
What are Wall Ties?
Wall ties are essential components in cavity wall building, connecting the inner and outer leaves of brickwork. These little but important parts, usually constructed of steel or stainless steel, support the structural integrity of buildings by transferring lateral loads and maintaining the stability of the wall system.
Signs of Wall Tie Failure
Visible Signs of Wall Tie Failure
Cracking
Horizontal cracks in walls, particularly those aligned with the position of wall ties, are a telltale sign of failure. These cracks may appear in mortar joints or across bricks themselves.
Wall Distortion
Bowed, bulging, or leaning walls indicate significant stress on the structure, often resulting from compromised wall ties.
Loose Masonry
Individual bricks or blocks that appear loose or can be easily moved suggest a loss of structural integrity, potentially due to wall tie issues.
Damp Patches
Moisture penetration through the cavity can lead to damp patches or staining on internal walls, signalling potential wall tie problems.
Hidden Signs for Wall Tie Failure
Corrosion
The rusting and expansion of metal ties within the cavity can cause unseen structural distortions and weakening.
Poor Ventilation
Inadequate airflow within the cavity can lead to moisture accumulation, accelerating tie deterioration.
Causes of Wall Tie Failure in Briston, Cardiff and South Wales
Corrosion
Corrosion is the main reason wall ties fail. When moisture and oxygen get trapped in the cavity wall, they attack the metal ties, causing them to rust. This is particularly severe in coastal areas where salt in the air speeds up corrosion. Buildings within 5km of the coast are most at risk, with corrosion happening up to three times faster than inland. Places with high rainfall or humidity also face increased risk as the constant moisture promotes rust formation.
Ground Movement
When the ground beneath a building moves or settles unevenly, it puts unusual stress on wall ties. These ties are designed to hold walls together, not cope with twisting or bending forces. Think of it like trying to bend a paperclip back and forth - eventually, it will break. Clay soils are especially problematic as they shrink in dry weather and expand when wet, constantly moving the building's foundations.
Poor Installation
Many wall tie problems start with incorrect installation. Modern standards require at least 2.5 ties per square metre, embedded at least 62.5mm into each wall. However, older buildings often have fewer ties installed at insufficient depths. The ties must also slope slightly downward toward the outer wall to let water drain away. When installed level or sloping inward, they can channel water into the building.
Material Problems
Older buildings, especially those built between 1920 and 1981, typically used galvanised steel ties. These have a protective zinc coating that lasts about 25-30 years. Once this coating wears away, the steel underneath rusts quickly. Modern buildings use stainless steel ties which last much longer and resist corrosion better.
Expansion
As ties rust, they expand to up to seven times their original size. This expansion puts pressure on the surrounding brickwork, often causing horizontal cracks along the mortar joints. Once cracking starts, more water can get in, making the problem worse. It's a bit like rust forming on a car - as it spreads, it forces body panels apart and lets in more water, accelerating the damage.
Progressive Failure
Wall tie failure usually starts in one area and spreads. When some ties fail, the remaining ones have to carry more weight. This extra stress causes them to fail faster, creating a domino effect. Early warning signs include horizontal cracks in mortar joints, bulging walls, or gaps between internal walls and external brickwork.
Regular inspections can catch these problems early, particularly in buildings over 30 years old or in coastal areas. Modern stainless steel ties and proper installation techniques have greatly reduced these issues in newer buildings, but older properties remain at risk.
Get Expert Guidance
If you suspect wall tie issues in your property in Cardiff, Swansea, Bristol or the surrounding areas, or wish to prevent potential problems, seek expert advice and solutions. Contact us today via our contact form or call us on 07852 229017.
