Replacement of failed wall ties
Survey-led recommendations
Established since 1989
What is a cavity wall?
Cavity walls are a common form of brickwork; most dwellings built after the 1920s will be of cavity wall construction. Cavity walls consist of two separate leaves, internal and external, which are tied together by cavity wall ties. Cavity walls have many benefits, such as providing better thermal insulation, helping prevent penetrating moisture ingress due to the space between leaves and the use of weep holes.
Cavity wall ties
Wall ties are a necessary component within a cavity wall construction. Spaced equally throughout the span of the wall, they are designed to tie the internal and external leaves together to help keep the structure safe and stable.
The image to the right is from a wall tie survey undertaken by Halton Construction & Surveying Services Ltd, which shows a severely corroded heavy-gauge fish-ail metal wall tie in its ash-based mortar bed joint.
Wall tie surveys
Wall tie surveys carried out by Halton Construction & Surveying Services Ltd start at £200.00 + VAT. Our company is a member of the Wall Tie Installers Federation and can offer a 25-year insurance-backed guarantee from the federation. All our wall-tie work is carried out in accordance with BRE Digest No. 329 and No. 401, including appropriate pull testing.
Pull Testing: This testing applies tension on a newly installed wall tie to help identify the load capacity before failure occurs to ensure the ties are suitable for use. Alongside wall tie surveys and testing, our team also carries out structural alterations and repairs, giving you a reliable solution for improving stability and long-term performance across Widnes.
Cavity wall tie failure
Wall tie failure is a common problem; steel and iron are the most common materials used for wall ties. Failure may be a result of poor workmanship during construction, rusting/corrosion or a chemical reaction where black ash mortar is used. Black ash-based mortar is commonly found in older buildings. The aggressive nature of the mortar due to the high sulphur properties may attack the galvanised coating of the wall ties and the metal, resulting in failure of the ties.
Maintaining the quality of wall ties is essential as failure may make dwellings less weathertight or cause a potential danger to occupants and passers-by, as the structure may become unstable. Vertical or horizontal cracks in brickwork and mortar joints, bulging brickwork, cracks or separation of window reveals, or sagging of lintels within the structure may indicate wall tie failure. Professional diagnosis alongside specialist equipment is required to investigate suspected wall tie failure in order to advise on remedial works before the issue escalates.
The images below show wall ties that were taken from remedial wall tie works undertaken by us. As you can see from the images, the level of corrosion is varied; tie 2 has expanded significantly, showing a higher rate of failure. A corroding metal tie may expand up to 7 times its original size, resulting in many defects within the structure.
We can provide the necessary high-quality services required in order to investigate suspected wall tie failure. The condition of wall ties can only be judged by visual inspection of the metal tie. This can either be done by using an advanced optical borescope or by removing the brickwork or mortar from the external leaf of the wall. A detailed survey report will be produced, with recommendations regarding the condition of the wall ties and any remedial works.
Get clarity on the condition of your walls
Contact Halton Construction & Surveying Services Ltd to arrange cavity wall tie replacement.
