Many old buildings today feature cavity walls which are walls with a space between them. This little cavity between walls had multiple benefits from rainwater protection to weather insulation. Now, these internal and external walls are connected with the help of wall ties. Consider them clips, holding the outer wall with their ends bedded into the internal wall. Without these ties, the outer wall will collapse. Moreover, they also give much-needed insulation from rainwater or thermal exchanges.
These wall ties are made commonly from metal which can be rusted over the years. Now, there is a procedure for rusted wall tie replacement but before it looms the question is, how do we know that they are rusted? The answer to this question is quite obvious. Just take a closer observation of your wall. If you see any cracks along the mortar if the ties are failing. Moreover, the symmetry of the wall will appear to change, giving it a bulging appearance. You can also confirm your suspicions by getting a wall tie survey.
Why is it necessary to replace rusted ties?
Wall ties are essential to maintain the structural stability of the space. Rusted wall ties will lead to their failure to hold both components of the wall firmly and ultimately outer wall will collapse. Buckling and bulging of walls are fairly common giving it an unpleasing look. Cracking and distortion leading to weight shifting all lead to wall collapse. Moreover, it will reduce the thermal insulation capabilities of the wall. Water will pass onto the cavity, accelerating the rusting along the way. By ignoring the rusted ties, the problem will keep growing leading to the overall failure of the structure.
Causes of Tie Failure
Although many reasons contribute to the failure, we can point out two of the most common.
- Most issues start from the beginning if the ties are not installed properly. Too much or too little spacing, wrong positioning of ties along with the quality of mortar used are the most fundamental issues.
- Wall ties are mostly made of metals coated with zinc to prevent corrosion. After some time, the coatings fall off exposing the metal to all sorts of reactants. Metal shifts position upon corrosion leading to loss of stability. Nowadays, stainless steel wall ties are used to have a better track record than coated metal ones.
How to prevent Wall Tie Failure?
The earlier you deal with wall tie failures, the better. Over time, the problem aggravates leading to more damage. The endpoint is the complete failure of the external wall. In the beginning, it is convenient to replace the corroded ties with new ones but once the corrosion spreads beyond normal, the repairing costs add up. Firstly, the initial installation should be on the point at strategic positions to hold the wall. Secondly, good quality ties should be used. Stainless steel ties have a considerable lifetime but for best results, use stainless steel ties with neoprene ends.
