Uh-Oh Cavity Wall Tie Failure

When a series of horizontal cracks appear on an external brick wall with a cavity construction, cavity tie failure is often diagnosed. This is a serious structural defect that needs to be fully investigated by an expert before a reputable building contractor is employed to implement a proposed remedial plan.

Wall ties commonly fail due to corrosion caused by oxidisation. Corroding ties produced from round wire may simply erode and disintegrate without any signs of the structural defect being visible. Eventually the tie will rot and the connection between the masonry's internal and external skins are lost. At that point he external façade of the structure becomes vulnerable to bowing and stability-damage by high wind loadings.

Tie irons that are manufactured from plate steel do leave typical 'tell tale' signs of a problem. Layers of iron oxide gradually build up on the base steel, dramatically increasing its mass in terms of plate thickness. The aggregate corrosive expansion forces, along a course containing a row of cavity ties, are sufficient to split the brickwork and slightly lift the wall. The damaging, continuing process weakens the structure and in severe winds can even contribute to the total collapse of the wall, posing a serious safety risk.

If hairline horizontal cracking is noticed within mortar beds, the first step is to contact a well-established and trusted and qualified surveyor who is able to carry out an intrusive survey for cavity tie failure and an assessment of its effect. This will determine the cause and extent of the cracking and the surveyor will be able to design and prescribe a suitable remedial solution. Careful consideration should be given to choosing a trusted building contractor as wall ties replacement is a process that should be carried out with care.

Twistfix are proud suppliers of 'easy-to-use' products for the repair, renovation, construction and restoration industries. All of our products undergo extensive independent testing to ensure that they meet and exceed all quality standards as well as strictly adhering to our own internal protocols and health, safety requirement. With a comprehensive range of masonry repair solutions available, we continue to provide the UK refurbishment industry building products of professional quality at the most competitive price.