Wall Tie Failure
The cause of wall tie failure a combination of the lack of quality control during the construction phase which meant that often too few ties were fitted, and poor quality materials used in manufacturing the ties.
As many as 2 million properties in United Kingdom may be suffering Wall Tie corrosion or failure and are in need of remedial stabilisation.
The problem is often made worse when insufficient Wall Ties have been used during the construction.
The absence of sufficient and effective wall ties may result in the structural failure of the wall and possible collapse.
Wall ties that have begun to corrode can expand up to ten times their original thickness; this process is the cause of the step cracking associated with wall tie failure.
Coastal locations with salt-laden driven rain also cause wall ties to corrode.
Intona has been heavily involved with the installation of remedial wall ties, in both private and City Council contracts. Our surveyor is certificated through ANCON for the survey and installation of remedial wall ties. Surveys involve borescope and metal detection to determine the condition of the original ties.
Identifying Wall Tie failure
Look for :
- Horizontal cracking at regular intervals to the external mortar joints typically around windows and doors.
- Outward bulging of the affected walls
- The lifting of roofs as a result of the lamination of the wall ties due to corrosion.
- Internal cracking that corresponds with external cracking.
The property needs to be inspected by a competent remedial surveyor using a metal detector and an endoscope to locate and examine the existing ties. Where replacement is necessary the surveyor will select from a range of stainless steel mechanical or resin fixed ties to suit the type and condition of masonry involved.
It is most important during the wall tie replacement works that the original ties are located and isolated to stop any further expansion that will lift the brickwork any further.