One of the leading causes of damage to brickwork and masonry is the corrosion of wall ties. Although they are designed to improve stability, a tie made of galvanised mild steel can suffer from corrosion once the protective layer is worn away. The steel will expand when this occurs, resulting in cracked bricks and mortar joints. The Churchill Concrete Technology team has seen this issue many times though and can provide professional brick and masonry repairs as a response.
The problem with wall tie failure is quite serious in the UK. A BRE report claims that of the 10 million homes built with cavity walls, around 2 million or 20% suffer from corrosion problems. This is due to the use mild steel ties and poor installation. The level of moisture can also be a big issue.
Wall tiles have improved a great deal recently though. Now products are available made from different metals with higher corrosion resistance as well as plastics that won’t corrode at all. Work is still needed to improve installation standards though to further reduce the risk of problems.
If brick and masonry repairs become necessary because of cracks caused by tie corrosion there are a number of options. The best is to use remedial wall ties to replace the corroded ones. That way it is possible to reinforce the stability and ensure the new components won’t have the same vulnerability.
There are several different types of remedial wall ties to choose from. They include;
Mechanical – they work by expansion
Resin bonded (or grouted) – non-expansive and require an adhesive fix
Friction fix or screw in – best for use with concrete or cement blockwork
Grouted sock anchors – combine mechanical and chemical anchoring
Starter ties – for installation into exposed walls before the second leaf is created to form a cavity
It is important to select the right ties, taking into account what materials have been used, how wide the cavity is, and the presence of exterior coatings or insulation. That way stability and longevity can improve.
If you need any brick or masonry repairs please contact the Churchill Concrete Technology team. We will visit to conduct a survey and determine exactly what service is needed. If wall ties are to blame we can install the right remedial ones for you.