Wall Tie failure may come up on a survey
What Are Cavity Wall Ties?
Cavity wall ties are usually made of mild steel and inserted in the cavity space linking the external wall of a property to its internal wall.
Older wall ties are of a flat fishtail design, whilst more modern design is twisted wire butterfly pattern. As cavity wall ties are expected to be exposed to water they are galvanised to resist corrosion. Over time, the galvanising can break down leading to wall tie failure.
Cavity wall tie corrosion is the term used when the cavity wall ties bedded in a property with a cavity wall construction corrode due to the breakdown of their protective coating. Wall tie corrosion can crack external walls.
How To Identify Cavity Wall Tie Failure
There are a number of signs to help determine if your property is affected:
•Horizontal Cracks – in the mortar, usually at high level caused by expansion of wall ties.
•Bulging brickwork – caused by snapped wall ties, which have corroded. This can make your property unstable.
Wall Ties Survey
A wall tie surveyor will carry out a thorough inspection to establish the need for remedial work.
The surveyor will:
•Complete a thorough examination of your property, inspecting random wall ties with an endoscope.
•Identify cracks and damage to brickwork.
•Provide the most effective treatment for wall tie failure.
Wall Tie Replacement
Treatment will include:
•Drilling holes in brickwork for access to wall ties (using the appropriate access equipment where needed)
•Installation of new stainless steel wall ties
•Isolation of existing wall ties to prevent further damage
•Preserving the appearance of your property – make drilled holes good to match the existing wall appearance